My officemate told me about this SuperWaba which is a Virtual Machine for PDA's. The syntax for developing apps is similar to the Java syntax. However, this VM doesn't implement any of Sun's specification. It is opensource but I don't think it's free.It works on old versions of Palm OS! See the list of their supported devices. I read in their website that you could use common Java IDE's in developing for this platform but as to which IDE's, I have no clue. Hmmmm... This should be interesting.