hello
first , i apologize for my bad english.
i work in a company and we have just finished a software for a project . this software is written in visual c++ 6 and because of long duration in completing it and changing of design parameters and personnel this software is not well designed at all. we want to produce a new version af this software with new software designing ( we have the algoritms ).
we want the new version to be portable to linux and the time factor is very important for us and the money is not 'very' important. we have very little expreince in linux envirement.our programm have a interface with hardware , is multithread and have a gui with self designed components ( charts and special diagrams and so). these are my questions :
1- should we use a crossplatform or should we use vc again and then port it to linux?
2- if we should use a crossplatform which one is better for us and why?

i will be very happy if you can help us in this situation.

i dont know what way you work most productive but i think in general you are better off if you develop once and compile for several platforms. For this you may use QT4 available for some money with different license versions at www.trolltech.com. A cheaper alternative is available at www.wxwidgets.org for free.
I once tried out QT3 and found it very attractive. (KDE is built on qt3 libraries.
Cheers,J.

Heres what I would do, uninstall VS 6 and burn the discs; it was microsoft's interpretation of what the C++ standard maybe before it was released. Porting anything from VS6 is just going to take more time, even to another Windows C++ compiler never mind Linux.

For cross platfrom threads look either at Boost or pthread_win32.

I'd also agree with the above sentiments:

a) Forget Visual C++ is you want portability
b) Select QT4 for portability

With QT4 you can still develop in Windows and then port the code over to Linux with little or no change to your code. Off the top of my head the main area of conflict between the two O/Ses would be the slash and backslash used in path names, and case sensitivity in Linux with file names. If you ensure that it works with Linux, then it will work with Windows.