FlashDevelop is an integrated development environment (IDE) for development of Adobe Flash websites, web applications, desktop applications and video games. The resulting applications run in Adobe Flash Player or Adobe AIR, on Microsoft Windows, Mac OS X, Android or iOS. The primary purpose of FlashDevelop is enabling developers to edit, compile, debug and publish a Flash ActionScript project. It supports ActionScript 2.0, ActionScript 3.0, Haxe and other upcoming languages. It has code completion, syntax highlighting, snippets and other features similar to Microsoft Visual Studio. FlashDevelop is free and open source software, mostly written in C# and is built on the efficient Scintilla editor component. It is extensible with a plugin architecture and is a .NET Framework 2.0 application only available for Microsoft Windows. As an open source project with a modular plugin system, users are able to improve and optimize the program, as well as write plugins for features that may be missing. The project is primarily funded by donations. FlashDevelop uses the free Adobe Flex SDK to build ActionScript 3 and MXML applications, the free MTASC compiler to build ActionScript 2 applications, and the free Haxe toolkit to build ActionScript 3, PHP, Neko or JavaScript applications. It also has code completion and highlighting for XML, HTML, PHP, and CSS.