Toublo is an image and animation editor specially designed for LED-displays.
ToubloScript can also be used to extend Toublo in various ways, such as visualizing custom non-linear or non 2D-displays. We make heavy use of this on our swarmcube project.
The best way to experience Toublo is to simple download it and try it out. You can compile Toublo from source - get it from our subversion repository - but it's more convinient to download an installer. We have installers for Linux and OS X.
(Note to Windows users: Windows is not tested and things may be broken. If you want to try it anyway, get the Linux installer and rename the .sh file to .jar. Just doubleclicking it should do it).