Hello,

C> Currently I am developing a mrp II application on windows platform using
C> delphi and firebird. But I need to rewrite program in other programming
C> language and support both linux and windows.

are these two both requirements or rather the former is "derived" from
the latter? IOW do you need to change language for reasons you haven't
stated or would you like to keep pascal-ing? If so, as Marius has
pointed out, FPC and (to a lesser extent) the Lazarus IDE are pretty
much usable right now. And you could port the code more easily.

If you prefer to change language, I suggest you forget about C and
concentrate on Java, Python, C++ (in ascending order of supposed
difficulty for one who comes from Delphi). About GUI toolkits, I have
to say that wxWidgets lacks a lot of OO features, but it works and
it's solid.

Ciao
--
Nando Dessena
http://www.flamerobin.org