REALbasic is wonderful at cross-platform programming. With a little elbow-grease it’s possible to make very nice Windows and Mac OS X applications. That’s the bread and butter of my business.
I have one client, however, that has had me working on a commercial VB6 application for five years. Since we know that someday VB6 will not be adequate for our needs we’re looking for the ‘next’ development environment. .NET is the easy answer but since I have a lot invested in RB so I thought that if I can get them halfway to cross-platform that would be a win-win for everyone.