diff --git a/configure.ac b/configure.ac
index 53fe4c5..a61d1fb 100644
--- a/configure.ac
+++ b/configure.ac
@@ -651,6 +651,7 @@ if test "x$enable_cookies" = "xno" ; then
 fi
 if test "x$enable_ipv6" = "xyes" ; then
   CFLAGS="$CFLAGS -DENABLE_IPV6"
+  CXXFLAGS="$CXXFLAGS -DENABLE_IPV6"
 fi
 if test "x$enable_efence" = "xyes" ; then
   LIBS="-lefence $LIBS"
@@ -708,7 +709,7 @@ dnl -----------
 dnl
 
 if eval "test x$GCC = xyes"; then
-  CXXFLAGS="$CXXFLAGS -Wall -W -Wno-unused-parameter -fno-rtti -fno-exceptions -pedantic -D_POSIX_C_SOURCE=200112L"
+  CXXFLAGS="$CXXFLAGS -Wall -W -Wno-unused-parameter -fno-rtti -fno-exceptions -pedantic -D_POSIX_C_SOURCE=200112L -std=c++23"
 fi
 
 dnl ----------------------------------
diff --git a/dlib/Makefile.am b/dlib/Makefile.am
index 5f7d1bc..f03030d 100644
--- a/dlib/Makefile.am
+++ b/dlib/Makefile.am
@@ -5,4 +5,4 @@ noinst_LIBRARIES = libDlib.a
 
 libDlib_a_SOURCES = \
 	dlib.h \
-	dlib.c
+	dlib.cc
diff --git a/dlib/dlib.c b/dlib/dlib.cc
similarity index 100%
rename from dlib/dlib.c
rename to dlib/dlib.cc
diff --git a/dpi/datauri.c b/dpi/datauri.c
index a7a9a4d..7743102 100644
--- a/dpi/datauri.c
+++ b/dpi/datauri.c
@@ -20,7 +20,7 @@
 
 #include "../dpip/dpip.h"
 #include "dpiutil.h"
-#include "../src/misc.h"
+#include "../src/misc.hh"
 
 /*
  * Debugging macros
diff --git a/src/IO/Makefile.am b/src/IO/Makefile.am
index 21beffa..ff0277c 100644
--- a/src/IO/Makefile.am
+++ b/src/IO/Makefile.am
@@ -27,7 +27,7 @@ libDiof_a_SOURCES = \
 	mime.h \
 	about.c \
 	Url.h \
-	http.c \
+	http.cc \
 	tls.h \
 	tls.c \
 	$(TLS_OPENSSL) \
diff --git a/src/IO/Url.h b/src/IO/Url.h
index 140a6ac..61b2655 100644
--- a/src/IO/Url.h
+++ b/src/IO/Url.h
@@ -2,7 +2,7 @@
 #define __IO_URL_H__
 
 #include "../chain.h"
-#include "../url.h"
+#include "../url.hh"
 #include "../../dlib/dlib.h"
 
 #ifdef __cplusplus
diff --git a/src/IO/http.c b/src/IO/http.cc
similarity index 88%
rename from src/IO/http.c
rename to src/IO/http.cc
index 7c51756..930707f 100644
--- a/src/IO/http.c
+++ b/src/IO/http.cc
@@ -36,9 +36,9 @@
 #include "../dns.h"
 #include "../web.hh"
 #include "../cookies.h"
-#include "../auth.h"
+#include "../auth.hh"
 #include "../prefs.h"
-#include "../misc.h"
+#include "../misc.hh"
 
 #include "../uicmd.hh"
 
@@ -177,7 +177,7 @@ static int Http_sock_new(void)
 static int Http_fd_map_cmp(const void *v1, const void *v2)
 {
    int fd = VOIDP2INT(v2);
-   const FdMapEntry_t *e = v1;
+   const FdMapEntry_t *e = reinterpret_cast< const FdMapEntry_t * >( v1 );
 
    return (fd != e->fd);
 }
@@ -214,15 +214,15 @@ static void Http_fd_map_remove_entry(int fd)
 void a_Http_connect_done(int fd, bool_t success)
 {
    SocketData_t *sd;
-   FdMapEntry_t *fme = dList_find_custom(fd_map, INT2VOIDP(fd),
-                                            Http_fd_map_cmp);
+   FdMapEntry_t *fme = reinterpret_cast< FdMapEntry_t * >( dList_find_custom(fd_map, INT2VOIDP(fd),
+                                            Http_fd_map_cmp) );
 
-   if (fme && (sd = a_Klist_get_data(ValidSocks, fme->skey))) {
+   if (fme && (sd = reinterpret_cast< SocketData_t * >( a_Klist_get_data(ValidSocks, fme->skey) ))) {
       ChainLink *info = sd->Info;
       bool_t valid_web = a_Web_valid(sd->web);
 
       if (success && valid_web) {
-         a_Chain_bfcb(OpSend, info, &sd->SockFD, "FD");
+         a_Chain_bfcb(OpSend, info, &sd->SockFD, const_cast< void * >( static_cast< const void * >( "FD" ) ));
          Http_send_query(sd);
       } else {
          if (valid_web)
@@ -230,7 +230,7 @@ void a_Http_connect_done(int fd, bool_t success)
          MSG("fd %d is done and failed\n", sd->SockFD);
          dClose(fd);
          Http_socket_free(VOIDP2INT(info->LocalKey)); /* free sd */
-         a_Chain_bfcb(OpAbort, info, NULL, "Both");
+         a_Chain_bfcb(OpAbort, info, NULL, const_cast< void * >( static_cast< const void * >( "Both" ) ));
          dFree(info);
       }
    } else {
@@ -257,7 +257,7 @@ static void Http_connect_queued_sockets(Server_t *srv)
         (i < dList_length(srv->queue) &&
          srv->active_conns < prefs.http_max_conns);
         i++) {
-      sd = dList_nth_data(srv->queue, i);
+      sd = reinterpret_cast< SocketData_t * >( dList_nth_data(srv->queue, i) );
 
       if (sd->flags & HTTP_SOCKET_TO_BE_FREED) {
          dList_remove(srv->queue, sd);
@@ -297,7 +297,7 @@ static void Http_socket_free(int SKey)
 {
    SocketData_t *S;
 
-   if ((S = a_Klist_get_data(ValidSocks, SKey))) {
+   if ((S = reinterpret_cast< SocketData_t * >( a_Klist_get_data(ValidSocks, SKey) ))) {
       a_Klist_remove(ValidSocks, SKey);
 
       if (S->flags & HTTP_SOCKET_IOWATCH_ACTIVE) {
@@ -363,7 +363,7 @@ static Dstr *Http_make_content_type(const DilloUrl *url)
       if (URL_DATA(url)->len > 2) {
          /* boundary lines have "--" prepended. Skip that. */
          const char *start = URL_DATA(url)->str + 2;
-         char *eol = strchr(start, '\r');
+         const char *eol = strchr(start, '\r');
          if (eol)
             dStr_append_l(dstr, start, eol - start);
       } else {
@@ -504,14 +504,14 @@ static void Http_send_query(SocketData_t *S)
 static void Http_connect_tls(ChainLink *info)
 {
    int SKey = VOIDP2INT(info->LocalKey);
-   SocketData_t *S = a_Klist_get_data(ValidSocks, SKey);
+   SocketData_t *S = reinterpret_cast< SocketData_t * >( a_Klist_get_data(ValidSocks, SKey) );
 
    if (S->flags & HTTP_SOCKET_USE_PROXY) {
       char *connect_str = Http_get_connect_str(S->url);
       DataBuf *dbuf = a_Chain_dbuf_new(connect_str, strlen(connect_str), 0);
 
       MSG_BW(S->web, 1, "Tunnel secure connection through proxy...");
-      a_Chain_bfcb(OpSend, info, &S->SockFD, "FD");
+      a_Chain_bfcb(OpSend, info, &S->SockFD, const_cast< void * >( static_cast< const void * >( "FD" ) ));
       S->https_proxy_reply = dStr_new(NULL);
       a_Chain_bcb(OpSend, info, dbuf, NULL);
 
@@ -529,7 +529,7 @@ static void Http_connect_tls(ChainLink *info)
 static void Http_connect_socket_cb(int fd, void *data)
 {
    int SKey = VOIDP2INT(data);
-   SocketData_t *S = a_Klist_get_data(ValidSocks, SKey);
+   SocketData_t *S = reinterpret_cast< SocketData_t * >( a_Klist_get_data(ValidSocks, SKey) );
 
    if (S) {
       int ret, connect_ret;
@@ -567,9 +567,9 @@ static void Http_connect_socket_cb(int fd, void *data)
 static void Http_connect_socket(ChainLink *Info)
 {
    DilloHost *dh;
-   SocketData_t *S = a_Klist_get_data(ValidSocks, VOIDP2INT(Info->LocalKey));
+   SocketData_t *S = reinterpret_cast< SocketData_t * >( a_Klist_get_data(ValidSocks, VOIDP2INT(Info->LocalKey)) );
 
-   for (; (dh = dList_nth_data(S->addr_list, S->addr_list_idx));
+   for (; (dh = reinterpret_cast< DilloHost * >( dList_nth_data(S->addr_list, S->addr_list_idx) ));
         S->addr_list_idx++) {
 #ifdef ENABLE_IPV6
       struct sockaddr_in6 name;
@@ -612,6 +612,7 @@ static void Http_connect_socket(ChainLink *Info)
 #ifdef ENABLE_IPV6
       case AF_INET6:
       {
+         MSG("Doing 6 connect...\n");
          char buf[128];
          struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&name;
          socket_len = sizeof(struct sockaddr_in6);
@@ -623,6 +624,8 @@ static void Http_connect_socket(ChainLink *Info)
             MSG("Connecting to [%s]:%u\n", buf, S->connect_port);
          break;
       }
+#else
+#error Flenser requires modern IP protocol.  Legacy IP protocol is deprecated.
 #endif
       } /* switch */
       MSG_BW(S->web, 1, "Contacting host...");
@@ -643,7 +646,9 @@ static void Http_connect_socket(ChainLink *Info)
             S->flags |= HTTP_SOCKET_IOWATCH_ACTIVE;
             break;
          } else {
-            MSG("Http_connect_socket connect ERROR: %s\n", dStrerror(errno));
+            MSG("Http_connect_socket connect ERROR: %s %d\n", dStrerror(errno), errno);
+            MSG("Http_connect_socket connect args: %d %p %d(fam) %d\n", S->SockFD, reinterpret_cast< void * >( &name ),
+					reinterpret_cast< struct sockaddr * >( &name )->sa_family, socket_len );
             MSG("We will try another IP address.\n");
          }
       }
@@ -739,7 +744,7 @@ static void Http_dns_cb(int Status, Dlist *addr_list, void *data)
    SocketData_t *S;
    Server_t *srv;
 
-   S = a_Klist_get_data(ValidSocks, SKey);
+   S = reinterpret_cast< SocketData_t * >( a_Klist_get_data(ValidSocks, SKey) );
    if (S) {
       const char *host = URL_HOST((S->flags & HTTP_SOCKET_USE_PROXY) ?
                                   HTTP_Proxy : S->url);
@@ -763,7 +768,7 @@ static void Http_dns_cb(int Status, Dlist *addr_list, void *data)
          ChainLink *info = S->Info;
 
          Http_socket_free(SKey);
-         a_Chain_bfcb(OpAbort, info, NULL, "Both");
+         a_Chain_bfcb(OpAbort, info, NULL, const_cast< void * >( static_cast< const void * >( "Both" ) ));
          dFree(info);
       }
    }
@@ -782,9 +787,9 @@ static int Http_get(ChainLink *Info, void *Data1)
    char *hostname;
    const DilloUrl *url;
 
-   S = a_Klist_get_data(ValidSocks, VOIDP2INT(Info->LocalKey));
+   S = reinterpret_cast< SocketData_t * >( a_Klist_get_data(ValidSocks, VOIDP2INT(Info->LocalKey)) );
    /* Reference Web data */
-   S->web = Data1;
+   S->web = reinterpret_cast< DilloWeb * >( Data1 );
    /* Reference Info data */
    S->Info = Info;
 
@@ -819,17 +824,17 @@ static int Http_get(ChainLink *Info, void *Data1)
  * This is not built to accept arbitrary sockets.
  */
 static bool_t Http_socket_reuse_compatible(SocketData_t *old,
-                                           SocketData_t *new)
+                                           SocketData_t *new_)
 {
    /*
     * If we are using TLS through a proxy, we need to ensure that old and new
     * are going through to the same host:port.
     */
-   if (a_Web_valid(new->web) &&
+   if (a_Web_valid(new_->web) &&
        ((old->flags & HTTP_SOCKET_TLS) == 0 ||
         (old->flags & HTTP_SOCKET_USE_PROXY) == 0 ||
-        ((URL_PORT(old->url) == URL_PORT(new->url)) &&
-         !dStrAsciiCasecmp(URL_HOST(old->url), URL_HOST(new->url)))))
+        ((URL_PORT(old->url) == URL_PORT(new_->url)) &&
+         !dStrAsciiCasecmp(URL_HOST(old->url), URL_HOST(new_->url)))))
       return TRUE;
    return FALSE;
 }
@@ -840,7 +845,7 @@ static bool_t Http_socket_reuse_compatible(SocketData_t *old,
  */
 static void Http_socket_reuse(int SKey)
 {
-   SocketData_t *new_sd, *old_sd = a_Klist_get_data(ValidSocks, SKey);
+   SocketData_t *new_sd, *old_sd = reinterpret_cast< SocketData_t * >( a_Klist_get_data(ValidSocks, SKey) );
 
    if (old_sd) {
       Server_t *srv = Http_server_get(old_sd->connected_to,
@@ -849,7 +854,7 @@ static void Http_socket_reuse(int SKey)
       int i, n = dList_length(srv->queue);
 
       for (i = 0; i < n; i++) {
-         new_sd = dList_nth_data(srv->queue, i);
+         new_sd = reinterpret_cast< SocketData_t * >( dList_nth_data(srv->queue, i) );
 
          if (!(new_sd->flags & HTTP_SOCKET_TO_BE_FREED) &&
              Http_socket_reuse_compatible(old_sd, new_sd)) {
@@ -886,7 +891,7 @@ void a_Http_ccc(int Op, int Branch, int Dir, ChainLink *Info,
    SocketData_t *sd;
    DataBuf *dbuf;
 
-   dReturn_if_fail( a_Chain_check("a_Http_ccc", Op, Branch, Dir, Info) );
+   dReturn_if_fail( a_Chain_check(const_cast< char * >( "a_Http_ccc" ), Op, Branch, Dir, Info) );
 
    if (Branch == 1) {
       if (Dir == BCK) {
@@ -922,10 +927,10 @@ void a_Http_ccc(int Op, int Branch, int Dir, ChainLink *Info,
          switch (Op) {
          case OpAbort:
             _MSG("ABORT 1F\n");
-            if ((sd = a_Klist_get_data(ValidSocks, SKey)))
+            if ((sd = reinterpret_cast< SocketData_t * >( a_Klist_get_data(ValidSocks, SKey) )))
                MSG_BW(sd->web, 1, "Can't get %s", URL_STR(sd->url));
             Http_socket_free(SKey);
-            a_Chain_fcb(OpAbort, Info, NULL, "Both");
+            a_Chain_fcb(OpAbort, Info, NULL, const_cast< void * >( static_cast< const void * >( "Both" ) ));
             dFree(Info);
             break;
          default:
@@ -935,13 +940,13 @@ void a_Http_ccc(int Op, int Branch, int Dir, ChainLink *Info,
       }
    } else if (Branch == 2) {
       if (Dir == FWD) {
-         sd = a_Klist_get_data(ValidSocks, SKey);
+         sd = reinterpret_cast< SocketData_t * >( a_Klist_get_data(ValidSocks, SKey) );
          assert(sd);
          /* Receiving from server */
          switch (Op) {
          case OpSend:
             if (sd->https_proxy_reply) {
-               dbuf = Data1;
+               dbuf = reinterpret_cast< DataBuf * >( Data1 );
                dStr_append(sd->https_proxy_reply, dbuf->Buf);
                if (strstr(sd->https_proxy_reply->str, "\r\n\r\n")) {
                   if (sd->https_proxy_reply->len >= 12 &&
@@ -959,13 +964,13 @@ void a_Http_ccc(int Op, int Branch, int Dir, ChainLink *Info,
                      MSG("CONNECT through proxy failed. Server sent:\n%s\n",
                          sd->https_proxy_reply->str);
                      Http_socket_free(SKey);
-                     a_Chain_bfcb(OpAbort, Info, NULL, "Both");
+                     a_Chain_bfcb(OpAbort, Info, NULL, const_cast< void * >( static_cast< const void * >( "Both" ) ));
                      dFree(Info);
                   }
                }
             } else {
                /* Data1 = dbuf */
-               a_Chain_fcb(OpSend, Info, Data1, "send_page_2eof");
+               a_Chain_fcb(OpSend, Info, Data1, const_cast< void * >( static_cast< const void * >( "send_page_2eof" ) ));
             }
             break;
          case OpEnd:
@@ -975,7 +980,7 @@ void a_Http_ccc(int Op, int Branch, int Dir, ChainLink *Info,
                    sd->https_proxy_reply->len ? sd->https_proxy_reply->str :
                    "(nothing)");
                Http_socket_free(SKey);
-               a_Chain_bfcb(OpAbort, Info, NULL, "Both");
+               a_Chain_bfcb(OpAbort, Info, NULL, const_cast< void * >( static_cast< const void * >( "Both" ) ));
             } else {
                Http_socket_free(SKey);
                a_Chain_fcb(OpEnd, Info, NULL, NULL);
@@ -990,7 +995,7 @@ void a_Http_ccc(int Op, int Branch, int Dir, ChainLink *Info,
                    "(nothing)");
             }
             Http_socket_free(SKey);
-            a_Chain_fcb(OpAbort, Info, NULL, "Both");
+            a_Chain_fcb(OpAbort, Info, NULL, const_cast< void * >( static_cast< const void * >( "Both" ) ));
             dFree(Info);
             break;
          default:
@@ -1005,13 +1010,13 @@ void a_Http_ccc(int Op, int Branch, int Dir, ChainLink *Info,
             break;
          case OpSend:
             if (Data2) {
-               if (!strcmp(Data2, "FD")) {
+               if (!strcmp(reinterpret_cast< const char * >( Data2 ), "FD")) {
                   int fd = *(int*)Data1;
-                  FdMapEntry_t *fme = dList_find_custom(fd_map, INT2VOIDP(fd),
-                                                        Http_fd_map_cmp);
+                  FdMapEntry_t *fme = reinterpret_cast< FdMapEntry_t * >( dList_find_custom(fd_map, INT2VOIDP(fd),
+                                                        Http_fd_map_cmp) );
                   Info->LocalKey = INT2VOIDP(fme->skey);
                   a_Chain_bcb(OpSend, Info, Data1, Data2);
-               } else if (!strcmp(Data2, "reply_complete")) {
+               } else if (!strcmp(reinterpret_cast< const char * >( Data2 ), "reply_complete")) {
                   a_Chain_bfcb(OpEnd, Info, NULL, NULL);
                   Http_socket_reuse(SKey);
                   dFree(Info);
@@ -1043,7 +1048,7 @@ static void Http_socket_enqueue(Server_t *srv, SocketData_t* sock)
       int i, n = dList_length(srv->queue);
 
       for (i = 0; i < n; i++) {
-         SocketData_t *curr = dList_nth_data(srv->queue, i);
+         SocketData_t *curr = reinterpret_cast< SocketData_t * >( dList_nth_data(srv->queue, i) );
 
          if (a_Web_valid(curr->web) && (curr->web->flags & WEB_Image)) {
             dList_insert_pos(srv->queue, sock, i);
@@ -1082,7 +1087,7 @@ static void Http_server_remove(Server_t *srv)
 {
    SocketData_t *sd;
 
-   while ((sd = dList_nth_data(srv->queue, 0))) {
+   while ((sd = reinterpret_cast< SocketData_t * >( dList_nth_data(srv->queue, 0) ))) {
       dList_remove_fast(srv->queue, sd);
       dFree(sd);
    }
@@ -1099,7 +1104,7 @@ static void Http_servers_remove_all(void)
 
    while (dList_length(servers) > 0) {
       srv = (Server_t*) dList_nth_data(servers, 0);
-      while ((sd = dList_nth_data(srv->queue, 0))) {
+      while ((sd = reinterpret_cast< SocketData_t * >( dList_nth_data(srv->queue, 0) ))) {
          dList_remove(srv->queue, sd);
          dFree(sd);
       }
diff --git a/src/IO/mime.h b/src/IO/mime.h
index 3bb24da..d54a947 100644
--- a/src/IO/mime.h
+++ b/src/IO/mime.h
@@ -19,7 +19,7 @@ extern "C" {
 #endif /* __cplusplus */
 
 
-#include "../cache.h"
+#include "../cache.hh"
 
 typedef void* (*Viewer_t) (const char*, void*, CA_Callback_t*, void**);
 
diff --git a/src/IO/tls.h b/src/IO/tls.h
index 7f43282..a3dda0c 100644
--- a/src/IO/tls.h
+++ b/src/IO/tls.h
@@ -25,7 +25,7 @@
 extern "C" {
 #endif
 
-#include "../url.h"
+#include "../url.hh"
 
 #define TLS_CONNECT_NEVER -1
 #define TLS_CONNECT_NOT_YET 0
diff --git a/src/IO/tls_mbedtls.h b/src/IO/tls_mbedtls.h
index 07a0737..46f1717 100644
--- a/src/IO/tls_mbedtls.h
+++ b/src/IO/tls_mbedtls.h
@@ -19,7 +19,7 @@
 extern "C" {
 #endif
 
-#include "../url.h"
+#include "../url.hh"
 
 const char *a_Tls_mbedtls_version(char *buf, int n);
 void a_Tls_mbedtls_init(void);
diff --git a/src/IO/tls_openssl.h b/src/IO/tls_openssl.h
index 5b442cb..3bdeea6 100644
--- a/src/IO/tls_openssl.h
+++ b/src/IO/tls_openssl.h
@@ -29,7 +29,7 @@
 extern "C" {
 #endif
 
-#include "../url.h"
+#include "../url.hh"
 
 const char *a_Tls_openssl_version(char *buf, int n);
 void a_Tls_openssl_init(void);
diff --git a/src/Makefile.am b/src/Makefile.am
index b4bb978..72bad4c 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -43,8 +43,8 @@ dillo_SOURCES = \
 	actions.h \
 	hsts.c \
 	hsts.h \
-	auth.c \
-	auth.h \
+	auth.cc \
+	auth.hh \
 	md5.c \
 	md5.h \
 	digest.c \
@@ -52,8 +52,8 @@ dillo_SOURCES = \
 	colors.c \
 	colors.h \
 	binaryconst.h \
-	misc.c \
-	misc.h \
+	misc.cc \
+	misc.hh \
 	history.h \
 	history.c \
 	prefs.c \
@@ -64,8 +64,8 @@ dillo_SOURCES = \
 	keys.hh \
 	msg.h \
 	list.h \
-	url.c \
-	url.h \
+	url.cc \
+	url.hh \
 	bitvec.c \
 	bitvec.h \
 	klist.c \
@@ -84,8 +84,8 @@ dillo_SOURCES = \
 	web.hh \
 	nav.c \
 	nav.h \
-	cache.c \
-	cache.h \
+	cache.cc \
+	cache.hh \
 	decode.c \
 	decode.h \
 	dicache.c \
diff --git a/src/auth.c b/src/auth.cc
similarity index 95%
rename from src/auth.c
rename to src/auth.cc
index 3b4ae66..3305d9e 100644
--- a/src/auth.c
+++ b/src/auth.cc
@@ -18,9 +18,9 @@
 
 
 #include <ctype.h> /* iscntrl, isascii */
-#include "auth.h"
+#include "auth.hh"
 #include "msg.h"
-#include "misc.h"
+#include "misc.hh"
 #include "dialog.hh"
 #include "digest.h"
 #include "../dlib/dlib.h"
@@ -359,7 +359,7 @@ static AuthHost_t *Auth_host_by_url(const DilloUrl *url)
    AuthHost_t *host;
    int i;
 
-   for (i = 0; (host = dList_nth_data(auth_hosts, i)); i++)
+   for (i = 0; (host = reinterpret_cast< AuthHost_t * >( dList_nth_data(auth_hosts, i) )); i++)
       if (((dStrAsciiCasecmp(URL_SCHEME(url), host->scheme) == 0) &&
            (dStrAsciiCasecmp(URL_AUTHORITY(url), host->authority) == 0)))
          return host;
@@ -376,7 +376,7 @@ static AuthRealm_t *Auth_realm_by_name(const AuthHost_t *host,
    AuthRealm_t *realm;
    int i;
 
-   for (i = 0; (realm = dList_nth_data(host->realms, i)); i++)
+   for (i = 0; (realm = reinterpret_cast< AuthRealm_t * >( dList_nth_data(host->realms, i) )); i++)
       if (strcmp(realm->name, name) == 0)
          return realm;
 
@@ -394,10 +394,10 @@ static AuthRealm_t *Auth_realm_by_path(const AuthHost_t *host,
    int match_length = 0;
 
    realm_best = NULL;
-   for (i = 0; (realm = dList_nth_data(host->realms, i)); i++) {
+   for (i = 0; (realm = reinterpret_cast< AuthRealm_t * >( dList_nth_data(host->realms, i) )); i++) {
       char *realm_path;
 
-      for (j = 0; (realm_path = dList_nth_data(realm->paths, j)); j++) {
+      for (j = 0; (realm_path = reinterpret_cast< char * >( dList_nth_data(realm->paths, j) )); j++) {
          int realm_path_length = strlen(realm_path);
          if (Auth_path_is_inside(path, realm_path, realm_path_length) &&
              !(realm_best && match_length >= realm_path_length)) {
@@ -433,7 +433,7 @@ static int Auth_realm_includes_path(const AuthRealm_t *realm, const char *path)
    int i;
    char *realm_path;
 
-   for (i = 0; (realm_path = dList_nth_data(realm->paths, i)); i++)
+   for (i = 0; (realm_path = reinterpret_cast< char * >( dList_nth_data(realm->paths, i) )); i++)
       if (Auth_path_is_inside(path, realm_path, strlen(realm_path)))
          return 1;
 
@@ -453,7 +453,7 @@ static void Auth_realm_add_path(AuthRealm_t *realm, const char *path)
       n_path[--len] = 0;
 
    /* delete existing paths that are inside the new one */
-   for (i = 0; (realm_path = dList_nth_data(realm->paths, i)); i++) {
+   for (i = 0; (realm_path = reinterpret_cast< char * >( dList_nth_data(realm->paths, i) )); i++) {
       if (Auth_path_is_inside(realm_path, path, len)) {
          dList_remove_fast(realm->paths, realm_path);
          dFree(realm_path);
@@ -635,7 +635,7 @@ static int Auth_do_auth_dialog(const AuthParse_t *auth_parse,
    data->url = a_Url_dup(url);
    ret = a_Dialog_user_password(title, msg, Auth_do_auth_dialog_cb, data);
    dFree(title); dFree(msg);
-   a_Url_free((void *)data->url);
+   a_Url_free(const_cast< DilloUrl * >( data->url ));
    dFree(data);
    return ret;
 }
@@ -673,11 +673,11 @@ int a_Auth_do_auth(Dlist *challenges, const DilloUrl *url)
    int i;
    char *chal;
 
-   for (i = 0; (chal = dList_nth_data(challenges, i)); ++i)
+   for (i = 0; (chal = reinterpret_cast< char * >( dList_nth_data(challenges, i) )); ++i)
       if (!dStrnAsciiCasecmp(chal, "Digest ", 7))
          if (Auth_do_auth(chal, DIGEST, url))
             return 1;
-   for (i = 0; (chal = dList_nth_data(challenges, i)); ++i)
+   for (i = 0; (chal = reinterpret_cast< char * >( dList_nth_data(challenges, i) )); ++i)
       if (!dStrnAsciiCasecmp(chal, "Basic ", 6))
          if (Auth_do_auth(chal, BASIC, url))
             return 1;
diff --git a/src/auth.h b/src/auth.hh
similarity index 82%
rename from src/auth.h
rename to src/auth.hh
index 03863e5..97a2968 100644
--- a/src/auth.h
+++ b/src/auth.hh
@@ -1,11 +1,6 @@
-#ifndef __AUTH_H__
-#define __AUTH_H__
+#pragma once
 
-#ifdef __cplusplus
-extern "C" {
-#endif /* __cplusplus */
-
-#include "url.h"
+#include "url.hh"
 
 enum AuthParseHTTPAuthType_t { TYPENOTSET, BASIC, DIGEST };
 enum AuthParseDigestAlgorithm_t { ALGORITHMNOTSET, MD5, MD5SESS };
@@ -33,8 +28,3 @@ char *a_Auth_get_auth_str(const DilloUrl *url, const char *request_uri);
 int a_Auth_do_auth(Dlist *auth_string, const DilloUrl *url);
 void a_Auth_init(void);
 
-
-#ifdef __cplusplus
-}
-#endif /* __cplusplus */
-#endif /* !__AUTH_H__ */
diff --git a/src/bw.h b/src/bw.h
index 83d9508..6980ee4 100644
--- a/src/bw.h
+++ b/src/bw.h
@@ -13,7 +13,7 @@
 #ifndef __BW_H__
 #define __BW_H__
 
-#include "url.h"     /* for DilloUrl */
+#include "url.hh"     /* for DilloUrl */
 
 /*
  * Flag Defines for a_Bw_stop_clients()
diff --git a/src/cache.c b/src/cache.cc
similarity index 95%
rename from src/cache.c
rename to src/cache.cc
index fd3a683..bf60bd7 100644
--- a/src/cache.c
+++ b/src/cache.cc
@@ -29,10 +29,10 @@
 #include "nav.h"
 #include "cookies.h"
 #include "hsts.h"
-#include "misc.h"
+#include "misc.hh"
 #include "capi.h"
 #include "decode.h"
-#include "auth.h"
+#include "auth.hh"
 #include "domain.h"
 #include "timeout.hh"
 #include "uicmd.hh"
@@ -96,7 +96,7 @@ static void Cache_entry_inject(const DilloUrl *Url, Dstr *data_ds);
  */
 static int Cache_entry_cmp(const void *v1, const void *v2)
 {
-   const CacheEntry_t *d1 = v1, *d2 = v2;
+   const CacheEntry_t *d1 = reinterpret_cast< const CacheEntry_t * >( v1 ), *d2 = reinterpret_cast< const CacheEntry_t * >( v2 );
 
    return a_Url_cmp(d1->Url, d2->Url);
 }
@@ -106,8 +106,8 @@ static int Cache_entry_cmp(const void *v1, const void *v2)
  */
 static int Cache_entry_by_url_cmp(const void *v1, const void *v2)
 {
-   const DilloUrl *u1 = ((CacheEntry_t*)v1)->Url;
-   const DilloUrl *u2 = v2;
+   const DilloUrl *u1 = reinterpret_cast< const CacheEntry_t * >( v1 )->Url;
+   const DilloUrl *u2 = reinterpret_cast< const DilloUrl * >( v2 );
 
    return a_Url_cmp(u1, u2);
 }
@@ -179,7 +179,7 @@ static void Cache_client_dequeue(CacheClient_t *Client)
 {
    if (Client) {
       dList_remove(ClientQueue, Client);
-      a_Web_free(Client->Web);
+      a_Web_free(reinterpret_cast< DilloWeb * >( Client->Web ));
       dFree(Client);
    }
 }
@@ -217,7 +217,7 @@ static void Cache_entry_init(CacheEntry_t *NewEntry, const DilloUrl *Url)
  */
 static CacheEntry_t *Cache_entry_search(const DilloUrl *Url)
 {
-   return dList_find_sorted(CachedURLs, Url, Cache_entry_by_url_cmp);
+   return reinterpret_cast< CacheEntry_t * >( dList_find_sorted(CachedURLs, Url, Cache_entry_by_url_cmp) );
 }
 
 /**
@@ -333,7 +333,7 @@ static void Cache_entry_remove(CacheEntry_t *entry, DilloUrl *url)
       return;
 
    /* remove all clients for this entry */
-   for (i = 0; (Client = dList_nth_data(ClientQueue, i)); ++i) {
+   for (i = 0; (Client = reinterpret_cast< CacheClient_t * >( dList_nth_data(ClientQueue, i) )); ++i) {
       if (Client->Url == entry->Url) {
          a_Cache_stop_client(Client->Key);
          --i;
@@ -377,7 +377,7 @@ int a_Cache_open_url(void *web, CA_Callback_t Call, void *CbData)
 {
    int ClientKey;
    CacheEntry_t *entry;
-   DilloWeb *Web = web;
+   DilloWeb *Web = reinterpret_cast< DilloWeb * >( web );
    DilloUrl *Url = Web->url;
 
    if (URL_FLAGS(Url) & URL_E2EQuery) {
@@ -766,9 +766,9 @@ static void Cache_parse_header(CacheEntry_t *entry)
    if ((Cookies = Cache_parse_multiple_fields(header, "Set-Cookie"))) {
       CacheClient_t *client;
 
-      for (i = 0; (client = dList_nth_data(ClientQueue, i)); ++i) {
+      for (i = 0; (client = reinterpret_cast< CacheClient_t * >( dList_nth_data(ClientQueue, i) )); ++i) {
          if (client->Url == entry->Url) {
-            DilloWeb *web = client->Web;
+            DilloWeb *web = reinterpret_cast< DilloWeb * >( client->Web );
 
             if (!web->requester ||
                 a_Url_same_organization(entry->Url, web->requester)) {
@@ -975,7 +975,7 @@ bool_t a_Cache_process_dbuf(int Op, const char *buf, size_t buf_size,
          int i;
          CacheClient_t *Client;
 
-         for (i = 0; (Client = dList_nth_data(ClientQueue, i)); ++i) {
+         for (i = 0; (Client = reinterpret_cast< CacheClient_t * >( dList_nth_data(ClientQueue, i) )); ++i) {
             if (Client->Url == entry->Url) {
                DilloWeb *web = (DilloWeb *)Client->Web;
 
@@ -1106,7 +1106,7 @@ int a_Cache_download_enabled(const DilloUrl *url)
  */
 static void Cache_null_client(int Op, CacheClient_t *Client)
 {
-   DilloWeb *Web = Client->Web;
+   DilloWeb *Web = reinterpret_cast< DilloWeb * >( Client->Web );
 
    /* make the stop button insensitive when done */
    if (Op == CA_Close) {
@@ -1145,7 +1145,7 @@ static void Cache_savelink_cb(void *vdata)
 static void Cache_provide_redirection_blocked_page(CacheEntry_t *entry,
                                                    CacheClient_t *client)
 {
-   DilloWeb *clientWeb = client->Web;
+   DilloWeb *clientWeb = reinterpret_cast< DilloWeb * >( client->Web );
 
    a_Web_dispatch_by_type("text/html", clientWeb, &client->Callback,
                           &client->CbData);
@@ -1155,7 +1155,7 @@ static void Cache_provide_redirection_blocked_page(CacheEntry_t *entry,
                     "</a> to <a href=\"", URL_STR(entry->Location), "\">",
                     URL_STR(entry->Location), "</a> based on your domainrc "
                     "settings.</body></html>", NULL);
-   client->BufSize = strlen(client->Buf);
+   client->BufSize = strlen(reinterpret_cast< const char * >( client->Buf ));
    (client->Callback)(CA_Send, client);
    dFree(client->Buf);
 }
@@ -1207,9 +1207,9 @@ static CacheEntry_t *Cache_process_queue(CacheEntry_t *entry)
    }
 
    Busy = TRUE;
-   for (i = 0; (Client = dList_nth_data(ClientQueue, i)); ++i) {
+   for (i = 0; (Client = reinterpret_cast< CacheClient_t * >( dList_nth_data(ClientQueue, i) )); ++i) {
       if (Client->Url == entry->Url) {
-         ClientWeb = Client->Web;    /* It was a (void*) */
+         ClientWeb = reinterpret_cast< DilloWeb * >( Client->Web );    /* It was a (void*) */
          Client_bw = ClientWeb->bw;  /* 'bw' in a local var */
 
          if (ClientWeb->flags & WEB_RootUrl) {
@@ -1401,9 +1401,9 @@ CacheClient_t *a_Cache_client_get_if_unique(int Key)
    int i, n = 0;
    CacheClient_t *Client, *iClient;
 
-   if ((Client = dList_find_custom(ClientQueue, INT2VOIDP(Key),
-                                   Cache_client_by_key_cmp))) {
-      for (i = 0; (iClient = dList_nth_data(ClientQueue, i)); ++i) {
+   if ((Client = reinterpret_cast< CacheClient_t * >( dList_find_custom(ClientQueue, INT2VOIDP(Key),
+                                   Cache_client_by_key_cmp) ))) {
+      for (i = 0; (iClient = reinterpret_cast< CacheClient_t * >( dList_nth_data(ClientQueue, i) )); ++i) {
          if (iClient->Url == Client->Url) {
             ++n;
          }
@@ -1423,8 +1423,8 @@ void a_Cache_stop_client(int Key)
    DICacheEntry *DicEntry;
 
    /* The client can be in both queues at the same time */
-   if ((Client = dList_find_custom(ClientQueue, INT2VOIDP(Key),
-                                   Cache_client_by_key_cmp))) {
+   if ((Client = reinterpret_cast< CacheClient_t * >( dList_find_custom(ClientQueue, INT2VOIDP(Key),
+                                   Cache_client_by_key_cmp) ))) {
       /* Dicache */
       if ((DicEntry = a_Dicache_get_entry(Client->Url, Client->Version)))
          a_Dicache_unref(Client->Url, Client->Version);
@@ -1451,13 +1451,13 @@ void a_Cache_freeall(void)
    void *data;
 
    /* free the client queue */
-   while ((Client = dList_nth_data(ClientQueue, 0)))
+   while ((Client = reinterpret_cast< CacheClient_t * >( dList_nth_data(ClientQueue, 0) )))
       Cache_client_dequeue(Client);
 
    /* Remove every cache entry */
    while ((data = dList_nth_data(CachedURLs, 0))) {
       dList_remove_fast(CachedURLs, data);
-      Cache_entry_free(data);
+      Cache_entry_free(reinterpret_cast< CacheEntry_t * >( data ));
    }
    /* Remove the cache list */
    dList_free(CachedURLs);
diff --git a/src/cache.h b/src/cache.hh
similarity index 99%
rename from src/cache.h
rename to src/cache.hh
index 5074eb0..7148ae0 100644
--- a/src/cache.h
+++ b/src/cache.hh
@@ -7,7 +7,7 @@ extern "C" {
 
 
 #include "chain.h"
-#include "url.h"
+#include "url.hh"
 
 /*
  * Cache Op codes
diff --git a/src/capi.h b/src/capi.h
index a50c751..86711a9 100644
--- a/src/capi.h
+++ b/src/capi.h
@@ -6,7 +6,7 @@ extern "C" {
 #endif /* __cplusplus */
 
 
-#include "cache.h"
+#include "cache.hh"
 #include "web.hh"
 
 /*
diff --git a/src/chain.h b/src/chain.h
index 0e938bd..0236e2e 100644
--- a/src/chain.h
+++ b/src/chain.h
@@ -1,6 +1,10 @@
 #ifndef __CHAIN_H__
 #define __CHAIN_H__
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /*
  * Concomitant control chain (CCC)
  * Theory and code by Jorge Arellano Cid <jcid@dillo.org>
@@ -73,4 +77,7 @@ int a_Chain_check(char *FuncStr, int Op, int Branch, int Dir,
 
 DataBuf *a_Chain_dbuf_new(void *buf, int size, int code);
 
+#ifdef __cplusplus
+}
+#endif
 #endif /* __CHAIN_H__ */
diff --git a/src/dgif.h b/src/dgif.h
index b02e611..06b5e73 100644
--- a/src/dgif.h
+++ b/src/dgif.h
@@ -5,7 +5,7 @@
 extern "C" {
 #endif /* __cplusplus */
 
-#include "url.h"
+#include "url.hh"
 #include "image.hh"
 
 
diff --git a/src/dialog.cc b/src/dialog.cc
index 6228f6e..109f142 100644
--- a/src/dialog.cc
+++ b/src/dialog.cc
@@ -16,6 +16,8 @@
 #include <math.h> // for rint()
 #include <string.h>
 
+#include <cassert>
+
 #include <memory>
 
 #include <FL/fl_ask.H>
@@ -33,7 +35,7 @@
 
 #include "msg.h"
 #include "dialog.hh"
-#include "misc.h"
+#include "misc.hh"
 #include "prefs.h"
 #include "dlib/dlib.h"
 
@@ -224,6 +226,8 @@ const char *a_Dialog_input(const char *title, const char *msg)
       input_str = dStrdup(c_inp->value());
       prefs.search_url_idx = ch->value();
    }
+   //delete b;
+   assert(window->contains(b));
    window.reset();
 
    return (input_answer == 1) ? input_str : NULL;
diff --git a/src/dicache.h b/src/dicache.h
index c940452..bcc03c2 100644
--- a/src/dicache.h
+++ b/src/dicache.h
@@ -8,7 +8,7 @@ extern "C" {
 
 #include "bitvec.h"
 #include "image.hh"
-#include "cache.h"
+#include "cache.hh"
 
 /** Symbolic name to request the last version of an image */
 #define DIC_Last  -1
diff --git a/src/digest.h b/src/digest.h
index 1afe4b5..4a991b6 100644
--- a/src/digest.h
+++ b/src/digest.h
@@ -1,9 +1,13 @@
 #ifndef __DIGEST_H__
 #define __DIGEST_H__
 
-#include "auth.h"
+#include "auth.hh"
 #include "../dlib/dlib.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 
 char *a_Digest_create_cnonce(void);
 int a_Digest_compute_digest(AuthRealm_t *realm,
@@ -13,4 +17,7 @@ char *a_Digest_authorization_hdr(AuthRealm_t *realm,
                                  const DilloUrl *url,
                                  const char *uri);
 
+#ifdef __cplusplus
+}
+#endif
 #endif /* !__DIGEST_H__ */
diff --git a/src/dillo.cc b/src/dillo.cc
index 14117bf..33f9839 100644
--- a/src/dillo.cc
+++ b/src/dillo.cc
@@ -45,7 +45,7 @@
 #include "prefsparser.hh"
 #include "keys.hh"
 #include "bw.h"
-#include "misc.h"
+#include "misc.hh"
 #include "history.h"
 #include "version.hh"
 
@@ -60,7 +60,7 @@
 #include "actions.h"
 #include "hsts.h"
 #include "domain.h"
-#include "auth.h"
+#include "auth.hh"
 #include "styleengine.hh"
 
 #include "dw/fltkcore.hh"
diff --git a/src/djpeg.h b/src/djpeg.h
index a22d105..ea879be 100644
--- a/src/djpeg.h
+++ b/src/djpeg.h
@@ -5,7 +5,7 @@
 extern "C" {
 #endif /* __cplusplus */
 
-#include "url.h"
+#include "url.hh"
 #include "image.hh"
 
 
diff --git a/src/domain.h b/src/domain.h
index f8e1fdf..3655592 100644
--- a/src/domain.h
+++ b/src/domain.h
@@ -6,7 +6,7 @@ extern "C" {
 #endif
 
 #include <stdio.h>
-#include "url.h"
+#include "url.hh"
 
 void a_Domain_parse(FILE *fp);
 void a_Domain_freeall(void);
diff --git a/src/dpng.h b/src/dpng.h
index 0b8a2dd..960f511 100644
--- a/src/dpng.h
+++ b/src/dpng.h
@@ -5,9 +5,9 @@
 extern "C" {
 #endif /* __cplusplus */
 
-#include "url.h"
+#include "url.hh"
 #include "image.hh"
-#include "cache.h"
+#include "cache.hh"
 
 
 void *a_Png_new(DilloImage *Image, DilloUrl *url, int version);
diff --git a/src/dsvg.h b/src/dsvg.h
index 2fe7c1a..4c886c4 100644
--- a/src/dsvg.h
+++ b/src/dsvg.h
@@ -5,7 +5,7 @@
 extern "C" {
 #endif /* __cplusplus */
 
-#include "url.h"
+#include "url.hh"
 #include "image.hh"
 
 
diff --git a/src/dwebp.h b/src/dwebp.h
index 3c89299..be77fc2 100644
--- a/src/dwebp.h
+++ b/src/dwebp.h
@@ -5,7 +5,7 @@
 extern "C" {
 #endif /* __cplusplus */
 
-#include "url.h"
+#include "url.hh"
 #include "image.hh"
 
 
diff --git a/src/form.cc b/src/form.cc
index 185def9..ce79bbc 100644
--- a/src/form.cc
+++ b/src/form.cc
@@ -21,7 +21,7 @@
 #include "dw/textblock.hh"
 
 #include "dlib/dlib.h"
-#include "misc.h"
+#include "misc.hh"
 #include "msg.h"
 #include "prefs.h"
 #include "uicmd.hh"
diff --git a/src/form.hh b/src/form.hh
index 7cb2bcc..13ca79f 100644
--- a/src/form.hh
+++ b/src/form.hh
@@ -1,7 +1,7 @@
 #ifndef __FORM_HH__
 #define __FORM_HH__
 
-#include "url.h"
+#include "url.hh"
 
 /*
  * Typedefs
diff --git a/src/gif.c b/src/gif.c
index d7d60cf..3bc531e 100644
--- a/src/gif.c
+++ b/src/gif.c
@@ -67,7 +67,7 @@
 
 #include "msg.h"
 #include "image.hh"
-#include "cache.h"
+#include "cache.hh"
 #include "dicache.h"
 
 #define INTERLACE      0x40
diff --git a/src/history.h b/src/history.h
index fbff563..0134034 100644
--- a/src/history.h
+++ b/src/history.h
@@ -2,7 +2,7 @@
 #ifndef __DILLO_HISTORY_H__
 #define __DILLO_HISTORY_H__
 
-#include "url.h"
+#include "url.hh"
 
 
 #ifdef __cplusplus
diff --git a/src/hsts.h b/src/hsts.h
index 3b2cf4b..b340915 100644
--- a/src/hsts.h
+++ b/src/hsts.h
@@ -2,7 +2,7 @@
 #define __HSTS_H__
 
 #include "d_size.h"
-#include "url.h"
+#include "url.hh"
 
 #ifdef __cplusplus
 extern "C" {
diff --git a/src/html.cc b/src/html.cc
index ab71ff6..8f11f4d 100644
--- a/src/html.cc
+++ b/src/html.cc
@@ -30,7 +30,7 @@
 #include "html_charrefs.h"
 #include "utf8.hh"
 
-#include "misc.h"
+#include "misc.hh"
 #include "uicmd.hh"
 #include "history.h"
 #include "menu.hh"
diff --git a/src/html.hh b/src/html.hh
index 67aeee6..5746130 100644
--- a/src/html.hh
+++ b/src/html.hh
@@ -13,7 +13,7 @@
 #ifndef __HTML_HH__
 #define __HTML_HH__
 
-#include "url.h"               // for DilloUrl
+#include "url.hh"               // for DilloUrl
 
 #ifdef __cplusplus
 extern "C" {
diff --git a/src/html_common.hh b/src/html_common.hh
index edf4007..393268a 100644
--- a/src/html_common.hh
+++ b/src/html_common.hh
@@ -14,7 +14,7 @@
 #ifndef __HTML_COMMON_HH__
 #define __HTML_COMMON_HH__
 
-#include "url.h"
+#include "url.hh"
 #include "bw.h"
 
 #include "lout/misc.hh"
diff --git a/src/image.hh b/src/image.hh
index 280fcef..3ba1b0d 100644
--- a/src/image.hh
+++ b/src/image.hh
@@ -24,7 +24,7 @@ extern "C" {
 
 
 #include "bitvec.h"
-#include "url.h"
+#include "url.hh"
 
 /*
  * Defines
diff --git a/src/jpeg.c b/src/jpeg.c
index d6fac82..3625f2f 100644
--- a/src/jpeg.c
+++ b/src/jpeg.c
@@ -33,7 +33,7 @@
 #endif
 
 #include "image.hh"
-#include "cache.h"
+#include "cache.hh"
 #include "dicache.h"
 #include "capi.h"       /* get cache entry status */
 #include "msg.h"
diff --git a/src/misc.c b/src/misc.cc
similarity index 99%
rename from src/misc.c
rename to src/misc.cc
index c4151f5..3dc1806 100644
--- a/src/misc.c
+++ b/src/misc.cc
@@ -17,7 +17,7 @@
 
 #include "utf8.hh"
 #include "msg.h"
-#include "misc.h"
+#include "misc.hh"
 
 /**
  * Escape characters as %XX sequences.
@@ -25,7 +25,7 @@
  */
 char *a_Misc_escape_chars(const char *str, const char *esc_set)
 {
-   static const char *const hex = "0123456789ABCDEF";
+   static const char hex[] = "0123456789ABCDEF";
    char *p = NULL;
    Dstr *dstr;
    int i;
@@ -136,7 +136,7 @@ typedef enum {
 int a_Misc_get_content_type_from_data(void *Data, size_t Size, const char **PT)
 {
    size_t i, non_ascci, non_ascci_text, bin_chars;
-   char *p = Data;
+   char *p = reinterpret_cast< char * >( Data );
    int st = 1;      /* default to "doubt' */
    DetectedContentType Type = DT_OCTET_STREAM; /* default to binary */
 
diff --git a/src/misc.h b/src/misc.hh
similarity index 81%
rename from src/misc.h
rename to src/misc.hh
index b1d6ee2..18981ee 100644
--- a/src/misc.h
+++ b/src/misc.hh
@@ -1,13 +1,7 @@
-#ifndef __DILLO_MISC_H__
-#define __DILLO_MISC_H__
+#pragma once
 
 #include <stddef.h>     /* for size_t */
 
-
-#ifdef __cplusplus
-extern "C" {
-#endif /* __cplusplus */
-
 #define d_isascii(c)  (((c) & ~0x7f) == 0) 
 
 char *a_Misc_escape_chars(const char *str, const char *esc_set);
@@ -21,10 +15,3 @@ int a_Misc_parse_geometry(char *geom, int *x, int *y, int *w, int *h);
 int a_Misc_parse_search_url(char *source, char **label, char **urlstr);
 char *a_Misc_encode_base64(const char *in);
 Dstr *a_Misc_file2dstr(const char *filename);
-
-#ifdef __cplusplus
-}
-#endif /* __cplusplus */
-
-#endif /* __DILLO_MISC_H__ */
-
diff --git a/src/plain.cc b/src/plain.cc
index b8478b5..fe75791 100644
--- a/src/plain.cc
+++ b/src/plain.cc
@@ -17,10 +17,10 @@
 
 #include "msg.h"
 #include "prefs.h"
-#include "cache.h"
+#include "cache.hh"
 #include "bw.h"
 #include "web.hh"
-#include "misc.h"
+#include "misc.hh"
 #include "styleengine.hh"
 
 #include "uicmd.hh"
diff --git a/src/png.c b/src/png.c
index d1faaf6..8db0e5f 100644
--- a/src/png.c
+++ b/src/png.c
@@ -27,7 +27,7 @@
 
 #include "msg.h"
 #include "image.hh"
-#include "cache.h"
+#include "cache.hh"
 #include "dicache.h"
 
 enum prog_state {
diff --git a/src/prefs.h b/src/prefs.h
index daa3070..d496fb5 100644
--- a/src/prefs.h
+++ b/src/prefs.h
@@ -13,7 +13,7 @@
 #ifndef __PREFS_H__
 #define __PREFS_H__
 
-#include "url.h"
+#include "url.hh"
 
 #ifdef __cplusplus
 extern "C" {
diff --git a/src/prefsparser.cc b/src/prefsparser.cc
index a7c7e5c..d910211 100644
--- a/src/prefsparser.cc
+++ b/src/prefsparser.cc
@@ -22,7 +22,7 @@
 #include <limits.h>
 
 #include "prefs.h"
-#include "misc.h"
+#include "misc.hh"
 #include "msg.h"
 #include "colors.h"
 
diff --git a/src/styleengine.cc b/src/styleengine.cc
index 0087b0b..be40c6a 100644
--- a/src/styleengine.cc
+++ b/src/styleengine.cc
@@ -13,7 +13,7 @@
 #include "../dlib/dlib.h"
 #include "msg.h"
 #include "prefs.h"
-#include "misc.h"
+#include "misc.hh"
 #include "html_common.hh"
 #include "styleengine.hh"
 #include "web.hh"
diff --git a/src/svg.c b/src/svg.c
index 9fffbe3..1c112ed 100644
--- a/src/svg.c
+++ b/src/svg.c
@@ -17,7 +17,7 @@
 
 #include "msg.h"
 #include "image.hh"
-#include "cache.h"
+#include "cache.hh"
 #include "dicache.h"
 
 #define NANOSVG_ALL_COLOR_KEYWORDS
diff --git a/src/uicmd.cc b/src/uicmd.cc
index 533de28..d9affad 100644
--- a/src/uicmd.cc
+++ b/src/uicmd.cc
@@ -45,7 +45,7 @@
 #include "history.h"
 #include "msg.h"
 #include "prefs.h"
-#include "misc.h"
+#include "misc.hh"
 #include "dlib/dlib.h"
 
 #include "dw/fltkviewport.hh"
diff --git a/src/url.c b/src/url.cc
similarity index 99%
rename from src/url.c
rename to src/url.cc
index 210785a..5b89c95 100644
--- a/src/url.c
+++ b/src/url.cc
@@ -46,9 +46,9 @@
 #include <string.h>
 #include <ctype.h>
 
-#include "url.h"
+#include "url.hh"
 #include "hsts.h"
-#include "misc.h"
+#include "misc.hh"
 #include "msg.h"
 
 static const char *HEX = "0123456789ABCDEF";
@@ -97,7 +97,7 @@ char *a_Url_str(const DilloUrl *u)
  */
 const char *a_Url_hostname(const DilloUrl *u)
 {
-   char *p;
+   const char *p;
    /* Internal url handling IS transparent to the caller */
    DilloUrl *url = (DilloUrl *) u;
 
@@ -603,7 +603,7 @@ char *a_Url_decode_hex_str(const char *str)
    }
    *dest++ = 0;
 
-   new_str = dRealloc(new_str, sizeof(char) * (dest - new_str));
+   new_str = reinterpret_cast< char * >( dRealloc(new_str, sizeof(char) * (dest - new_str)) );
    return new_str;
 }
 
diff --git a/src/url.h b/src/url.hh
similarity index 100%
rename from src/url.h
rename to src/url.hh
diff --git a/src/web.hh b/src/web.hh
index eba00f5..9f746e5 100644
--- a/src/web.hh
+++ b/src/web.hh
@@ -1,9 +1,8 @@
-#ifndef __WEB_H__
-#define __WEB_H__
+#pragma once
 
 #include <stdio.h>     /* for FILE */
 #include "bw.h"        /* for BrowserWindow */
-#include "cache.h"     /* for CA_Callback_t */
+#include "cache.hh"     /* for CA_Callback_t */
 #include "image.hh"    /* for DilloImage */
 
 #ifdef __cplusplus
@@ -47,4 +46,3 @@ int a_Web_dispatch_by_type (const char *Type, DilloWeb *web,
 #ifdef __cplusplus
 }
 #endif /* __cplusplus */
-#endif /* __WEB_H__ */
diff --git a/src/webp.c b/src/webp.c
index ba0adac..d8bdcae 100644
--- a/src/webp.c
+++ b/src/webp.c
@@ -19,7 +19,7 @@
 
 #include "msg.h"
 #include "image.hh"
-#include "cache.h"
+#include "cache.hh"
 #include "dicache.h"
 
 enum prog_state {