FlashDevelop is an open-source integrated development environment (IDE) designed primarily for programming in ActionScript and developing Adobe AIR applications. It is a Windows-based software offering features like syntax highlighting, code completion, and project management. FlashDevelop also supports Haxe development, making it a versatile tool for developers working on multimedia projects. The IDE provides extensibility through plugins, allowing users to customize their development experience. It is highly regarded for its speed and efficiency in handling Flash development workflows.