VERSION 2.5 IS OUT!!!!!!:
http://alertgames.net/index.php?page=s/pd2
This program helps you to design effects for your game, or even other things such as logos, banners, etc. It exports the script to the cliboard or to a gml file, making it easy to put the particle system right into your game. You can also take screenshots and use a code editor in the program.
It includes a easy to use and good looking interface, with a tab system and menu bar. It also contains a codebox for testing right inside the designer! You can even save the system and code in a pdsf file for PD. Have fun!
(The full version includes GIF animation, and multi image-format support for sprites and backgrounds)