C/C++

So my question is simple ; of the two which would be advisable to learn first.

All the C++ books tell me to learn C++ over C ,but on the internet im told that learning C gives better grasps of concepts.

Which should i learn first and why?

There are two compilers, GDC (http://dgcc.sourceforge.net/) and DMD (http://www.digitalmars.com/d/download.html).

Both are free (former as in speech, latter as in beer), and can be used to make commercial software. Since both use the same public domain frontend, they have similar bugcounts: http://dstress.kuehne.cn/www/dstress.html

However, the language is still very young. As much as I like it, I don't think you should write anything commercial in it just yet. Risk mitigation and all that.

tl;dr: yes, there are freely available compilers for linux and win32 that you can build commercial software with.