Ming
Ming is an open-source (LGPL) library which allows you to create SWF ("Flash") format movies. Ming supports almost all of Flash 4's features, including: shapes, gradients, bitmaps (pngs and jpegs), morphs ("shape tweens"), text, buttons, actions, sprites ("movie clips"), streaming mp3, and color transforms--the only thing that's missing is sound events. Ming contains wrappers for PHP, Zope/Python, Perl, Ruby, and c++. Ming is not an acronym. Also, Ming contains a Flash 5 actionscript compiler and support for clip event actions.