Projects / FLTK


FLTK (pronounced "fulltick") is a cross-platform C++ GUI toolkit for UNIX/Linux (X11), Microsoft Windows, and Mac OS X. It provides modern GUI functionality without the bloat, and supports 3D graphics via OpenGL and its built-in GLUT emulation. FLTK is designed to be small and modular enough to be statically linked, and also works fine as a shared library. It also includes an excellent UI builder called FLUID that can be used to create applications in minutes.

Operating Systems

RSS Recent releases

  •  10 Jul 2011 14:24

Release Notes: This release is a huge step in the FLTK 1 series. All strings in FLTK are now handled in UTF-8 format and support the full range of Unicode character sets everywhere. International input methods are supported on all platforms. Two new widgets were added: Fl_Tree and Fl_Table. Printing is now as easy as drawing into a window, and window printing of FLTK GUIs is supported, including OpenGL. Internally, FLTK has been upgraded to run on current Unices, Windows 7, and Mac OS X via Cocoa. All graphics calls now use device abstraction.

  •  28 Jun 2008 09:19

Release Notes: Improved color contrast in secondary selection blocks of Fl_Text_Display, a fix for a regression in callback handling, a fix for incorrect relative paths when the absolute path has a trailing slash in fl_filename_relative, a fix for multiple selection of files and directories in Fl_File_Chooser, and a fix for a crash under MS Windows when selecting umlauts in Fl_Help_View.

  •  27 Mar 2008 12:48

Release Notes: This release fixes many bugs, and improves OS X and Quartz compatibility and overall reliability. It has a new GTK+ style theme, better GLUT4 compatibility, and alpha blending for image maps. This is the final release of the 1.1.x development tree.

  •  17 Jan 2006 22:09

Release Notes: This release fixes many bugs, adds some new example programs, and adds many new improvements to the FLUID software, including multi-level undo, syntax highlighting in all code fields, widget alignment and sizing guides, dialog templates, widget subclasses, and printing and testing of user interfaces within FLUID.

  •  13 Dec 2004 01:15

Release Notes: This version adds a Fl::delete_widget() method to safely delete widgets in callback methods. It fixes a problem where Fl_Double_Window produced an error on resize with X11 FLUID didn't display menu items using images properly, an issue where FLUID didn't handle default function parameters properly, and a problem where FLTK windows could appear off-screen on X11. The configure script now supports --disable-localfoo to completely disable image file support. The scandir() conditional code was fixed for HP-UX 11i. There were some Open Watcom fixes, and some fixes for the library include order when building DSOs on MacOS X. fl_xid() no longer causes Win32 applications to crash.

RSS Recent comments

25 Nov 2002 12:13 Avatar dlekic Thumbs up

I think it's time for 2.0 version Mike...
I am getting tired of 1.x branch. There is FLTK v2.0 for SEVERAL YEARS! Mike, Bill, please let's start working on that! Pleaseeee!

23 Aug 2001 14:34 dlucio

It's a very nice GUI API Interface, much better than GTK I think. Documentation shourld be a better explan on EVENTs and other stuf.

30 Jun 2000 03:11 lars30

Installation of FLTK
Make sure you have the Mesa Development source available. glx.h needs to be around or the source won't compile.

31 Dec 1999 11:38 fratermisc Thumbs up

the documentation on the drawing functions
Documentation on the drawing functions (other than the GL widget which is very nicely explained in a batch of source code) is rather obscure in my opinion. The toolkit itself is a very good one and deserves to be absorbed in to wide use. Much better than GTK for rapidity of simple app development. As for complex apps I wouldn't know... yet.


Project Spotlight


Log monitoring made easy.


Project Spotlight


A digital e-portfolio builder and social networking application.