# FLTK

> Widget toolkit

**Wikidata**: [Q1331203](https://www.wikidata.org/wiki/Q1331203)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/FLTK)  
**Source**: https://4ort.xyz/entity/fltk

## Summary
FLTK (Fast Light Toolkit) is a free, open-source widget toolkit used to create graphical user interfaces (GUIs) for applications. It is designed to be lightweight, fast, and cross-platform, supporting operating systems like Windows, macOS, and Unix-like systems. Licensed under the GNU Lesser General Public License (LGPL), it allows developers to build custom interfaces with minimal resource usage.

## Key Facts
- **License**: GNU Lesser General Public License (LGPL), enabling free use, modification, and distribution.
- **Supported Platforms**: Microsoft Windows, macOS, and Unix-like operating systems.
- **Initial Release**: Version 1.0 launched on March 10, 1999.
- **Latest Stable Version**: 1.3.4-2 (as of 2018), with prior stable releases like 1.3.4-1 (November 15, 2016) and 1.3.3 (November 3, 2014).
- **Programming Languages**: Primarily C++ (referenced via Open Hub analysis).
- **Repository**: Hosted on GitHub at [https://github.com/fltk/fltk](https://github.com/fltk/fltk).
- **Package Availability**: Included in repositories for Debian, Ubuntu, Fedora, Gentoo, and macOS (Homebrew).

## FAQs
### Q: What platforms does FLTK support?
A: FLTK runs on Microsoft Windows, macOS, and Unix-like operating systems, ensuring cross-platform compatibility for GUI development.

### Q: Is FLTK free to use?
A: Yes, FLTK is free software licensed under the GNU LGPL, allowing users to run, modify, and distribute the toolkit and its applications.

### Q: What programming language is FLTK based on?
A: FLTK is primarily developed in C++, though it can be used with other languages through bindings.

## Why It Matters
FLTK plays a critical role in enabling efficient GUI development for applications requiring low resource overhead. Its cross-platform compatibility and lightweight design make it ideal for embedded systems, scientific tools, and projects prioritizing speed over complex visuals. As free software, it promotes accessibility and customization, fostering a community-driven ecosystem. FLTK’s longevity (since 1999) and active maintenance ensure its relevance in environments where newer, bulkier toolkits may be impractical.

## Notable For
- **Cross-Platform Consistency**: Applications built with FLTK maintain uniform functionality across Windows, macOS, and Unix-like systems.
- **Lightweight Design**: Optimized for minimal memory and CPU usage, making it suitable for resource-constrained environments.
- **Long-Term Support**: Continuous updates since 1999, with stable versions maintained for over two decades.
- **Extensive Packaging**: Available in official repositories for major Linux distributions (e.g., Debian, Ubuntu) and package managers like Homebrew.

## Body
### History and Development
- **Initial Release**: Version 1.0 debuted on March 10, 1999, followed by incremental updates (e.g., 1.0.1 on March 25, 1999) addressing bugs and adding features.
- **Stable Versions**: Notable releases include 1.3.3 (2014), 1.3.4-1 (2016), and 1.3.4-2 (2018), each refining stability and compatibility.

### Technical Features
- **Licensing**: Governed by the GNU LGPL, ensuring compatibility with both open-source and proprietary projects.
- **Language Support**: Built in C++, with community-developed bindings for other languages (e.g., Python, Ruby).

### Ecosystem and Distribution
- **Source Code**: Hosted on GitHub, facilitating community contributions and transparency.
- **Package Management**: Included in Linux distributions (e.g., `libfltk1.3` for Ubuntu) and macOS Homebrew (`fltk` formula).
- **Documentation and Tools**: Provides official documentation, example code, and development utilities for rapid application prototyping.

## References

1. [Source](http://www.fltk.org/COPYING.php)
2. [The fltk Open Source Project on Open Hub: Languages Page. Open Hub](https://www.openhub.net/p/fltk/analyses/latest/languages_summary)
3. [Source](http://www.fltk.org/articles.php?L1392+I0+T+P1+Q)
4. [Release 1.3.3. 2014](https://github.com/fltk/fltk/releases/tag/release-1.3.3)
5. [Source](http://www.fltk.org/articles.php?L1497)
6. [Release 1.3.4-1. 2016](https://github.com/fltk/fltk/releases/tag/release-1.3.4-1)
7. [Source](http://www.fltk.org/software.php)
8. [Release 1.0. 1999](https://github.com/fltk/fltk/releases/tag/release-1.0)
9. [Release 1.0.1. 1999](https://github.com/fltk/fltk/releases/tag/release-1.0.1)
10. [Release 1.0.2. 1999](https://github.com/fltk/fltk/releases/tag/release-1.0.2)
11. [Release 1.0.3. 1999](https://github.com/fltk/fltk/releases/tag/release-1.0.3)
12. [Release 1.0.4. 1999](https://github.com/fltk/fltk/releases/tag/release-1.0.4)
13. [Release 1.0.5. 1999](https://github.com/fltk/fltk/releases/tag/release-1.0.5)
14. [Release 1.0.6. 1999](https://github.com/fltk/fltk/releases/tag/release-1.0.6)
15. [Release 1.0.7. 1999](https://github.com/fltk/fltk/releases/tag/release-1.0.7)
16. [Release 1.0.8. 2000](https://github.com/fltk/fltk/releases/tag/release-1.0.8)
17. [Release 1.0.9. 2000](https://github.com/fltk/fltk/releases/tag/release-1.0.9)
18. [Release 1.0.10. 2000](https://github.com/fltk/fltk/releases/tag/release-1.0.10)
19. [Release 1.0.11. 2001](https://github.com/fltk/fltk/releases/tag/release-1.0.11)
20. [Release 1.1.0. 2002](https://github.com/fltk/fltk/releases/tag/release-1.1.0)
21. [Release 1.1.1. 2002](https://github.com/fltk/fltk/releases/tag/release-1.1.1)
22. [Release 1.1.2. 2002](https://github.com/fltk/fltk/releases/tag/release-1.1.2)
23. [Release 1.1.3. 2003](https://github.com/fltk/fltk/releases/tag/release-1.1.3)
24. [Release 1.1.4. 2003](https://github.com/fltk/fltk/releases/tag/release-1.1.4)
25. [Release 1.1.5. 2004](https://github.com/fltk/fltk/releases/tag/release-1.1.5)
26. [Release 1.1.6. 2004](https://github.com/fltk/fltk/releases/tag/release-1.1.6)
27. [Release 1.1.7. 2006](https://github.com/fltk/fltk/releases/tag/release-1.1.7)
28. [Release 1.1.8. 2008](https://github.com/fltk/fltk/releases/tag/release-1.1.8)
29. [Release 1.1.9. 2008](https://github.com/fltk/fltk/releases/tag/release-1.1.9)
30. [Release 1.1.10. 2009](https://github.com/fltk/fltk/releases/tag/release-1.1.10)
31. [Release 1.3.0. 2011](https://github.com/fltk/fltk/releases/tag/release-1.3.0)
32. [Release 1.3.1. 2012](https://github.com/fltk/fltk/releases/tag/release-1.3.1)
33. [Release 1.3.2. 2012](https://github.com/fltk/fltk/releases/tag/release-1.3.2)
34. [Release 1.3.4. 2016](https://github.com/fltk/fltk/releases/tag/release-1.3.4)
35. [Release 1.3.5. 2019](https://github.com/fltk/fltk/releases/tag/release-1.3.5)
36. [2021](https://github.com/fltk/fltk/releases/tag/release-1.3.8)
37. [FLTK 1.3.8 released on Nov. 20, 2021. 2021](https://www.fltk.org/articles.php?L1782)
38. [2023](https://www.fltk.org/articles.php?L1898)
39. [2023](https://github.com/fltk/fltk/releases/tag/release-1.3.9)
40. [FLTK 1.3.10 released on Nov. 16, 2024. 2024](https://www.fltk.org/articles.php?L1954)
41. [FLTK 1.4.0-1 released on Nov. 18, 2024. 2024](https://www.fltk.org/articles.php?L1955)
42. [Source](https://www.fltk.org/articles.php?L1959)
43. [Source](https://www.fltk.org/articles.php?L1972)
44. [Source](https://www.fltk.org/articles.php?L1984)
45. [Source](https://github.com/fltk/fltk/releases/tag/release-1.4.3)
46. [Source](https://www.fltk.org/articles.php?L1998)
47. Freebase Data Dumps. 2013
48. Quora