SOLARIS2
USG
USG5_4
+HAIKU Compiling on Haiku.
** Distinguishing GUIs **
NS_IMPL_GNUSTEP Compile support for GNUstep implementation of NS GUI API.
NS_IMPL_COCOA Compile support for Cocoa (Apple) implementation of NS GUI API.
HAVE_X11 Compile support for the X11 GUI.
+HAVE_PGTK Compile support for using GTK itself without directly using X Windows APIs.
+HAVE_HAIKU Compile support for the Haiku window system.
HAVE_X_WINDOWS Compile support for X Window system
(It looks like, nowadays, if HAVE_X11 is set, HAVE_X_WINDOWS must
be, and vice versa. At least, this is true for configure, and
msdos; not sure about nt.)
-HAVE_X11R6
-HAVE_X11R6_XIM
-HAVE_X11XTR6
+
+** X Windows features **
+HAVE_X11R6 Whether or not the system has X11R6. (Always defined.)
+HAVE_X11R6_XIM Whether or not the system supports XIM features introduced in R6.
+HAVE_X11XTR6 Whether or not the Xt is from X11R6 or newer.
+
USE_LUCID Use the Lucid toolkit for menus&scrollbars. Requires HAVE_X11.
USE_MOTIF Use the Motif toolkit for menus&scrollbars. Requires HAVE_X11.
-USE_GTK Use the Gtk toolkit for menus&scrollbars. Requires HAVE_X11.
+USE_GTK Use the Gtk toolkit for menus&scrollbars. Requires HAVE_X11 or HAVE_PGTK.
+HAVE_GTK3 Use GTK version 3 or later. Requires HAVE_X11.
+
+HAVE_XCB_SHAPE Whether or not XCB supports the Nonrectangular Window Shape extension.
+HAVE_XCOMPOSITE Whether or not the XCOMPOSITE extension library is present.
+HAVE_XDBE Whether or not to use the Xdbe extension for double buffering.
+HAVE_XFIXES Whether or not the Xfixes extension library is present.
+HAVE_XINERAMA Whether or not the Xinerama extension library is present.
+HAVE_XINPUT2 Whether or not to use version 2 of the X Input Extension for input.
+HAVE_XINPUT2_1 Whether or not version 2.1 of the X Input Extension is supported.
+HAVE_XINPUT2_2 Whether or not version 2.2 of the X Input Extension is supported.
+HAVE_XINPUT2_3 Whether or not version 2.3 of the X Input Extension is supported.
+HAVE_XINPUT2_4 Whether or not version 2.4 of the X Input Extension is supported.
+HAVE_XKB Whether or not the XKB extension library is present.
+HAVE_XRANDR Whether or not the RandR extension library is present.
+HAVE_XSHAPE Whether or not the Nonrectangular Window Shape extension library is present.
+HAVE_XSYNC Whether or not the X Synchronization Extension library is present.
+USE_XCB Whether or not the XCB library is used to optimize some X requests.
** Frame types **