Well, I made a program to help with different verb forms in Japanese, but it could only run on Windows... so here is a version using HTTP, which means any operating system can use it as long as they have a web browser and an internet connection! =D
Major credit goes to Rita L. Lampkin's book "Japanese Verbs & Essentials Of Grammar Second Edition".
This HTTP version is not complete yet! It is still in the developing stage.
It doesn't deal with desu, like the original program does, yet.
Latest info about this version: Lines are coloured by ending type (can be disabled).
If you're interested in what JVS is compatible with, please look here.