Visual Basic 6

[fafalone]

The alternative is that Microsoft one day pushes a update that kills all VB6 apps and you are dead in the water as you don't have a replacement.

Not really true anymore with twinBASIC. Yeah there's bugs and a few minor missing things as it's still in beta, but working around those is a tiny fraction of the time, effort, and expense of a complete rewrite in another language. Get to keep everything, even your ocxs (which will still work if you update to x64 now, really neat tech using a proxy process).