Borland License and commercial software

Hello all!
I'm developing my first commercial software for WinXX plataform, and I have some doubts about the compiler license.
I'm currently using the old Borland C++ 5.0 IDE (unregistered) and learning OWL. Is that ok to develop my commercial program using the bc5 w/o pay for license? and about the OWL? can I write a commercial software using OWL whitout pay for any license? well...since Borland C++ is not available anymore and the compiler is free....
I didn't really understood the Borland license agreement.
A friend told me to use the QT (trolltech) library but I cannot sell my software using the free version of QT.
What should I do? get a free compiler like djgpp?
I really could use some pro advice and I don't want put my foot out of the law.

Thanks,
Jester