First on Powerbuilder.
I don't know of any major corporations in my area that are developing new applications in Powerbuilder. There are still quite a few existing apps in the language. Most of the corps have tried over the years to convert PB apps to another platform, primarily the WEB. All PHB's know is to be followers and that is what PHB's in other corporations are attempting to do. They think everything should be a WEB app.
The problem is, converting a very rich desktop app to a WEB app is not trivial if you want to maintain similar functionality. In fact the cost will be several times the cost of the original development. The same problem applies to any rich desktop app, not just Powerbuilder.
A conversion may be justified for one primary reason, the lack of availability of competent programmers in PB, Delphi or other older language. The PHB's just need to understand that the cost of conversion will be high.
If converting an old app to a newer language is attempted, it makes more sense to use .NET as the target platform on the desktop. But that is another hot topic altogether.
I still make a good chunk of change maintaining PB applications.
On dBase.
dBase still lives! It has changed hands a few times but it still exists. The current form of the language is significantly different than the old language. You can create anything from a WEB app to a standard desktop app. Lots of features. The URL is still
dBase.com. The new dBase would not be used, or make any sense at all for a large corporation. It might make sense for a small developer producing a product for resale.