# fltk/fltk

FLTK - Fast Light Tool Kit - https://github.com/fltk/fltk - cross platform GUI development

Repository: https://github.com/fltk/fltk
Canonical: https://ross.abutalabs.com/products/fltk
Homepage: https://www.fltk.org
Language: C++
License: NOASSERTION
License Family: other
Last push: 2026-08-26T19:37:48+00:00

## Health v2 (maintenance only)
Score: 89/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 69, longevity 100
- inputs: {"age_days": 2906, "days_push": 7, "days_rel": 130, "gap_med": 54, "n_releases_24m": 8}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2264, forks 340 (observed 2026-08-28T04:06:32.527890+00:00)

## What it is
FLTK (Fast Light Tool Kit) is a cross-platform C++ GUI toolkit for Linux (X11/Wayland), Windows, and macOS, providing lightweight, modular GUI functionality with OpenGL 3D support and GLUT emulation. It includes FLUID, a UI builder, and is licensed under LGPL with static-linking exceptions.

## Use cases
- build a cross-platform desktop gui application in c++
- create lightweight native windows without heavy dependencies
- add opengl 3d rendering to a c++ desktop app
- statically link a gui toolkit into a small binary
- design ui layouts visually with a gui builder
- port a gui app across linux, windows, and macos

## When to choose
- you need a small, fast, statically-linkable C++ GUI toolkit
- you want cross-platform desktop support including X11 and Wayland
- you need OpenGL integration or GLUT emulation
- you prefer minimal dependencies and a mature, long-stable API

## When to avoid
- you need modern theming, touch, or mobile support
- you want a widget toolkit with rich built-in controls like data grids or web views
- you prefer declarative or reactive UI frameworks
- you need first-class accessibility support

## Facets
- artifact type: library
- maturity: stable
- function: ui-components, graphics, gui
- domain: cross-platform, desktop-applications, graphics, developer-tools
- platform: windows, cpp, cross-platform
- tags: gui-toolkit, opengl, fluid-ui-builder, x11, wayland, static-linking, lightweight, linux, macos

## Member repositories
- fltk/fltk (main) score 89

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:32.527890+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T02:42:26.721919+00:00, confidence not recorded.
  - readme: https://github.com/fltk/fltk (fetched 2026-08-28T04:06:32.527890+00:00, sha 6615fcf8eea0)
  - homepage: https://www.fltk.org (fetched 2026-08-29T10:22:51.483956+00:00, sha 6c4c1b3a2180)
  - site_page: https://www.fltk.org/documentation.php (fetched 2026-08-29T10:22:51.496745+00:00, sha e4d4cf1ad7f1)
  - site_page: https://www.fltk.org/articles.php (fetched 2026-08-29T10:22:51.493029+00:00, sha fda7689a02eb)
  - site_page: https://www.fltk.org/str.php (fetched 2026-08-29T10:22:51.494973+00:00, sha a7c26f73177c)
- Data as of 2026-08-30T08:39:29.467469+00:00.