Index: acinclude.m4
===================================================================
--- acinclude.m4	(revision 7737)
+++ acinclude.m4	(working copy)
@@ -206,10 +206,9 @@
   dnl AC_CHECK_LIB(m, main, echo)
   dnl AC_CHECK_LIB(z, main, echo)
 
-  C_LIB=-lc
+  GB_LIBC()
 
-  AC_SUBST(C_LIB)
-
+  dnl ---- Check for C++ libraries
   AC_CHECK_LIB(gcc_s, main, CXX_LIB="$CXX_LIB -lgcc_s")
   AC_CHECK_LIB(stdc++, main, CXX_LIB="$CXX_LIB -lstdc++")
 
@@ -370,6 +369,13 @@
       GBX_THREAD_INC="-pthread -D_REENTRANT"
       GBX_THREAD_LDFLAGS=""
       ;;
+    *-*-haiku* )
+      THREAD_LIB=""
+      THREAD_INC=""
+      GBX_THREAD_LIB=""
+      GBX_THREAD_INC=""
+      GBX_THREAD_LDFLAGS=""
+      ;;
     *)
       THREAD_LIB="-lpthread"
       THREAD_INC="-D_REENTRANT"
@@ -393,6 +399,30 @@
 
 
 ## ---------------------------------------------------------------------------
+## GB_LIBC
+## Detect C library
+## ---------------------------------------------------------------------------
+
+AC_DEFUN([GB_LIBC],
+[
+  case "${host}" in
+    *-*-haiku* )
+      dnl Haiku has implicit C library in libroot.
+      C_LIB=""
+      ;;
+    *)
+      C_LIB="-lc"
+      ;;
+  esac
+
+  AC_MSG_CHECKING(for C library)
+  AC_MSG_RESULT($C_LIB)
+
+  AC_SUBST(C_LIB)
+])
+
+
+## ---------------------------------------------------------------------------
 ## GB_MATH
 ## Detect mathematic libraries
 ## ---------------------------------------------------------------------------
@@ -403,6 +433,9 @@
     *-*-freebsd* )
       MATH_LIB="-lm"
       ;;
+    *-*-haiku* )
+      MATH_LIB=""
+      ;;
     *)
       MATH_LIB="-lm"
       ;;
@@ -521,6 +554,12 @@
       AC_DEFINE(OS_HURD, 1, [Target system is Hurd])
       AC_DEFINE(SYSTEM, "Hurd", [Operating system])
       ;;
+    *-*-haiku* )
+      SYSTEM=HAIKU
+      dnl AC_DEFINE(OS_GNU, 1, [Target system is of GNU family])
+      AC_DEFINE(OS_HAIKU, 1, [Target system is Haiku])
+      AC_DEFINE(SYSTEM, "Haiku", [Operating system])
+      ;;
     * )
       SYSTEM=UNKNOWN
       AC_DEFINE(SYSTEM, "unknown", [Operating system])
@@ -641,6 +680,18 @@
 
 gb_sub_dir_list_64=`echo "$gb_sub_dir_list" | sed s/"lib"/"lib64"/g`
 
+if test $SYSTEM == "HAIKU"; then
+  gb_arch="`getarch`"
+  gb_main_dir_list="$gb_main_dir_list `findpaths -c' ' -a "$gb_arch" B_FIND_PATH_DEVELOP_DIRECTORY`"
+  gb_arch_inc_subdir=headers
+  gb_arch_lib_subdir=lib
+  if test "$gb_arch" != "`getarch -p`"; then
+    gb_arch_inc_subdir="headers/$gb_arch"
+    gb_arch_lib_subdir="lib/$gb_arch"
+  fi
+  gb_sub_dir_list=`echo "$gb_sub_dir_list" | sed "s:include:$gb_arch_inc_subdir:g;s:lib:$gb_arch_lib_subdir:g"`
+fi
+
 ## if there is 'lib' inside sub-directories, then we decide to search "lib64" first.
 
 if test "$gb_sub_dir_list_64" != "$gb_sub_dir_list"; then
Index: gb.httpd/configure.ac
===================================================================
--- gb.httpd/configure.ac	(revision 7737)
+++ gb.httpd/configure.ac	(working copy)
@@ -96,7 +96,9 @@
 	    GB_AC_LBL_CHECK_LIB(socket, gethostbyname,
 		V_NETLIBS="-lsocket -lnsl $V_NETLIBS",
 		AC_CHECK_LIB(resolv, gethostbyname,
-		    V_NETLIBS="-lresolv $V_NETLIBS"),
+		    V_NETLIBS="-lresolv $V_NETLIBS",
+		    AC_CHECK_LIB(network, gethostbyname,
+			V_NETLIBS="-lnetwork V_NETLIBS")),
 		-lnsl))))
 AC_CHECK_FUNC(socket, ,
     AC_CHECK_LIB(socket, socket,
Index: gb.net/src/CDnsClient.c
===================================================================
--- gb.net/src/CDnsClient.c	(revision 7737)
+++ gb.net/src/CDnsClient.c	(working copy)
@@ -530,7 +530,7 @@
 	else
 	{ /* Synchronous mode */
 		inet_aton(THIS->sHostIP,&addr);
-#ifdef __sun__
+#if defined(__sun__) || defined(__HAIKU__)
 		stHost=gethostbyaddr((const char *)&addr,sizeof(addr),AF_INET);
 #else
 		stHost=gethostbyaddr(&addr,sizeof(addr),AF_INET);
Index: gb.net/src/CSerialPort.c
===================================================================
--- gb.net/src/CSerialPort.c	(revision 7737)
+++ gb.net/src/CSerialPort.c	(working copy)
@@ -42,6 +42,10 @@
 #define TIOCINQ FIONREAD
 #endif
 
+#ifndef TIOCM_RNG
+#define TIOCM_RNG TIOCM_RI
+#endif
+
 #include "main.h"
 #include "tools.h"
 
@@ -652,8 +656,12 @@
 
 	if (THIS->status)
 	{
+#ifdef TIOCINQ
 		if (ioctl(THIS->port, TIOCINQ, &ret))
 			GB.Error("Unable to read input buffer size: &1", strerror(errno));
+#else
+			GB.Error("Unable to read input buffer size: &1", strerror(ENOSYS));
+#endif
 	}
 
 	GB.ReturnInteger(ret);
@@ -666,8 +674,12 @@
 
 	if (THIS->status)
 	{
+#ifdef TIOCOUTQ
 		if (ioctl(THIS->port, TIOCOUTQ, &ret))
 			GB.Error("Unable to read output buffer size: &1", strerror(errno));
+#else
+			GB.Error("Unable to read output buffer size: &1", strerror(ENOSYS));
+#endif
 	}
 
 	GB.ReturnInteger(ret);
Index: gb.net/src/CSocket.c
===================================================================
--- gb.net/src/CSocket.c	(revision 7737)
+++ gb.net/src/CSocket.c	(working copy)
@@ -32,6 +32,7 @@
 #include <sys/socket.h>
 #include <sys/ioctl.h>
 #include <sys/poll.h>
+#include <sys/time.h>
 #include <sys/un.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
Index: gb.xml/src/element.cpp
===================================================================
--- gb.xml/src/element.cpp	(revision 7737)
+++ gb.xml/src/element.cpp	(working copy)
@@ -19,6 +19,7 @@
 
 ***************************************************************************/
 
+#define _GNU_SOURCE /* for memrchr() */
 #include "element.h"
 
 #include "node.h"
Index: gb.xml/src/html/cssfilter.cpp
===================================================================
--- gb.xml/src/html/cssfilter.cpp	(revision 7737)
+++ gb.xml/src/html/cssfilter.cpp	(working copy)
@@ -1,3 +1,4 @@
+#define _GNU_SOURCE /* for memrchr() */
 #include "cssfilter.h"
 #include "htmlmain.h"
 #include "htmlelement.h"
Index: gb.xml/src/utils.cpp
===================================================================
--- gb.xml/src/utils.cpp	(revision 7737)
+++ gb.xml/src/utils.cpp	(working copy)
@@ -19,6 +19,7 @@
 
 ***************************************************************************/
 
+#define _GNU_SOURCE /* for memrchr() */
 #include "utils.h"
 #include "gbinterface.h"
 #include "gb_common.h"
Index: main/configure.ac
===================================================================
--- main/configure.ac	(revision 7737)
+++ main/configure.ac	(working copy)
@@ -9,6 +9,14 @@
 LT_INIT 
 AM_PROG_CC_C_O
 
+dnl ---- Check for POSIX.1-2001 calls
+
+AC_CHECK_FUNCS(getpriority setpriority waitpid statvfs)
+
+dnl ---- Haiku needs -lbsd for daemon()
+
+AC_SEARCH_LIBS(daemon, bsd)
+
 dnl ---- Check for internationalization library
 
 GB_COMPONENT(
@@ -87,7 +95,7 @@
 dnl ---- We do not use libtool to load shared libraries anymore!
 
 AC_DEFINE(DONT_USE_LTDL, 1, [Do not use libtool to load shared libraries])
-if test "$SYSTEM" != "OPENBSD" && test "$SYSTEM" != "FREEBSD"; then
+if test "$SYSTEM" != "OPENBSD" && test "$SYSTEM" != "FREEBSD" && test "$SYSTEM" != "HAIKU"; then
   DL_LIB="-ldl"
 else
   DL_LIB=""
Index: main/gbc/gbi.c
===================================================================
--- main/gbc/gbi.c	(revision 7737)
+++ main/gbc/gbi.c	(working copy)
@@ -45,7 +45,7 @@
 
 #include <dlfcn.h>
 
-#if defined(OS_LINUX) || defined(OS_GNU) || defined(OS_OPENBSD) || defined(OS_FREEBSD) || defined(OS_CYGWIN)
+#if defined(OS_LINUX) || defined(OS_GNU) || defined(OS_OPENBSD) || defined(OS_FREEBSD) || defined(OS_CYGWIN) || defined(OS_HAIKU)
 	#define lt_dlinit() (0)
 	#define lt_dlhandle void *
 	#define lt_dlopenext(_path) dlopen(_path, RTLD_LAZY)
Index: main/gbx/gbx_c_application.c
===================================================================
--- main/gbx/gbx_c_application.c	(revision 7737)
+++ main/gbx/gbx_c_application.c	(working copy)
@@ -238,8 +238,12 @@
 		if (!_daemon && VPROP(GB_BOOLEAN))
 		{
 			old_pid = getpid();
+#ifdef HAVE_DAEMON
 			if (daemon(FALSE, FALSE))
 				THROW_SYSTEM(errno, NULL);
+#else
+			THROW_SYSTEM(ENOSYS, NULL);
+#endif
 			// Argh! daemon() changes the current process id...
 			_daemon = TRUE;
 			init_again(old_pid);
@@ -257,12 +261,16 @@
 
 BEGIN_PROPERTY(Application_Priority)
 
-	int pr;
+	int pr = -1;
 
 	if (READ_PROPERTY)
 	{
 		errno = 0;
+#ifdef HAVE_GETPRIORITY
 		pr = getpriority(PRIO_PROCESS, 0);
+#else
+		errno = ENOSYS;
+#endif
 		if (pr == -1 && errno > 0)
 			THROW_SYSTEM(errno, NULL);
 		GB_ReturnInteger(pr);
@@ -276,8 +284,12 @@
 		else if (pr > 19)
 			pr = 19;
 
+#ifdef HAVE_SETPRIORITY
 		if (setpriority(PRIO_PROCESS, 0, VPROP(GB_INTEGER)) < 0)
 			THROW_SYSTEM(errno, NULL);
+#else
+		THROW_SYSTEM(ENOSYS, NULL);
+#endif
 	}
 
 END_PROPERTY
Index: main/gbx/gbx_c_process.c
===================================================================
--- main/gbx/gbx_c_process.c	(revision 7737)
+++ main/gbx/gbx_c_process.c	(working copy)
@@ -834,7 +834,11 @@
 {
 	int status;
 
+#ifdef HAVE_WAITPID
+	if (waitpid(process->pid, &status, WNOHANG) == process->pid)
+#else
 	if (wait4(process->pid, &status, WNOHANG, NULL) == process->pid)
+#endif
 	{
 		process->status = status;
 		_last_status = status;
Index: main/gbx/gbx_c_task.c
===================================================================
--- main/gbx/gbx_c_task.c	(revision 7737)
+++ main/gbx/gbx_c_task.c	(working copy)
@@ -120,7 +120,11 @@
 	while (_object)
 	{
 		next = THIS->list.next;
+#ifdef HAVE_WAITPID
+		if (waitpid(THIS->pid, &status, WNOHANG) == THIS->pid)
+#else
 		if (wait4(THIS->pid, &status, WNOHANG, NULL) == THIS->pid)
+#endif
 		{
 			THIS->status = status;
 			stop_task(THIS);
Index: main/lib/signal/csignal.c
===================================================================
--- main/lib/signal/csignal.c	(revision 7737)
+++ main/lib/signal/csignal.c	(working copy)
@@ -42,7 +42,11 @@
 #define SIGPWR -1
 #endif
 
-#ifdef OS_CYGWIN
+#ifndef SIGIO
+#define SIGIO -1
+#endif
+
+#if defined(OS_CYGWIN) || defined(OS_HAIKU)
 #define SIGIOT -1
 #endif
 
Index: main/share/gb_file_temp.h
===================================================================
--- main/share/gb_file_temp.h	(revision 7737)
+++ main/share/gb_file_temp.h	(working copy)
@@ -39,7 +39,9 @@
 
 #ifdef PROJECT_EXEC
 
-#if defined(OS_FREEBSD) || defined(OS_OPENBSD)
+#ifdef HAVE_STATVFS
+#include <sys/statvfs.h>
+#elif defined(OS_FREEBSD) || defined(OS_OPENBSD)
 #include <sys/mount.h>
 #else
 #include <sys/statfs.h>
@@ -1077,12 +1079,20 @@
 
 int64_t FILE_free(const char *path)
 {
+#ifdef HAVE_STATVFS
+	struct statvfs info;
+#else
 	struct statfs info;
+#endif
 
 	if (FILE_is_relative(path))
 		return 0;
 
+#ifdef HAVE_STATVFS
+	statvfs(path, &info);
+#else
 	statfs(path, &info);
+#endif
 	return (int64_t)(getuid() == 0 ? info.f_bfree : info.f_bavail) * info.f_bsize;
 }