There is a lot of confusion, especially for people who are new to FLTK, about the different FLTK versions, what they offer, and when they will be released. This article attempts to clarify matters.

Jan 3, 2011 · We recommend to use the latest stable release FLTK 1.4.4, the first entry in the table below. Only old software should use 1.3.11, and only very old software may need older versions.

Jul 20, 2025 · FLTK 2.0 (never released) This branch has never been released and is no longer being maintained. Documentation retained for historical purposes only.

FLTK provides modern GUI functionality without bloat and supports 3D graphics via OpenGL® and its built-in GLUT emulation. It was originally developed by Mr. Bill Spitzak and is currently maintained by …

FLTK supports normal, embossed, and shadowed labels internally, and more types can be added as desired. A complete list of all label options can be found in the section on Labels and Label Types.

FLTK includes all of the usual widgets to develop your applications, and new widgets can be created easily through C++ subclassing. All widgets support keyboard shortcuts and can be controlled both …

FLTK is a LGPL'd C++ graphical user interface toolkit for X (UNIX®), Linux® (X11 and Wayland), macOS (aka OS X), OpenGL, and Windows (Microsoft® Windows® XP, 2000, and later). ...

The overlay test app shows how easy an FLTK window can be layered to display cursor and manipulator style elements. This example derives a new class from Fl_Overlay_Window and provides a new …

Jan 17, 2025 · This document defines the processes and standards that all FLTK developers must follow when developing and documenting FLTK, and how trouble reports are handled and releases are …

Apr 24, 2002 · FLTK stores the colors of widgets as an 32-bit unsigned number that is either an index into a color palette of 256 colors or a 24-bit RGB color. The color palette is not the X or WIN32 …