LinuxQuestions.org - How to program under Linux/Unix platform

Hi
I program for win32 using VC++ , including API functions MFC, ATL, DCOM,COM+ libraries.
My questions are:
What kind of levels are for Linux\Unix programming?
What is low level?(e.g. for Win32 API functions).
Do Linux\Unix platforms have API functions
What is POSIX? Can GUI be programed with POSIX
What kind of GUI be programed with POSIX 12?
What are system functions for Linux\Unix programming?What can be programmed with them???
What means X- Window GNOME KDE for Linux\Unix programming?
What kind of programming can be done with GTK, GTK+, Qt..? What library is most popular and effective?
What equivalents of win32 api functions and MFC and ATL are for Linux \Unix platforms??????????????????????????
What equivalents of DCOM and COM+ are for Linux \Unix platforms??????????????????????????
Is CORBA more popular than COM+ for Linux \Unix platforms?
Are available good implamentation of DCOM\COM+ for Linux\Unix platforms
What equivalents of Direct X and OpenGL are for Linux \Unix platforms????????????

What is difference between programming for Linux Red Hat and ASP and Mandrake and Free BSD and Solaris?????????????????????
So please give me the whole picture of Unix\Linux programming and libraries and tools available for it.

What are eqivalents of messages of win32 exist for Linux \Unix platforms?
Whate are signals in Linux \Unix platforms? How can the be used?????

Please explain for new man in Linux \Unix programming!!!!!!!!!!!!!!
I will be very grateful?
If you can please send me reoly on my E- mail:
igor_d007@excite.com

Igor