1)   ScriptMaker 2.01
ScriptMaker helps you develop, write and maintain your screenplay and format it to professional standards. It encourages annotation, which is used to navigate the script either via a tree structure or "virtual index cards".

 2)   Script Genie 1.6
Script Genie extends the capabilities of Microsoft Word to allow you to easily manage writing your screenplays, complete with automatic formatting of scene headers, dialogue, and other script elements.