FlashDevelop is the premiere open-source Adobe Flash ActionScript 2 Editor, and can be used to built websites and applications that target Flash Player 6-8 with ActionScript 2.

Features include:

• Code completion for AS2
  • Platform API (based on used Flash Player version)
  • User classes, methods, and variables
  • Events when working with listeners
• Code folding
• Code generation
• Syntax coloring
• Compiling & Publishing
  • Compile projects via Adobe Flash IDE
  • Compile ActionScript 2 projects to SWF using MTASC