Questions concerning licenses
 

Hello,

I released previous projects under GPL license. No problem with using other Open Source classes and so on.

But now I'm working on a project I'm planning to release under a commercial license.

It's a website written in php.

I can't use the GPL license because I don't want that customers are allowed to distribute the software. On the other hand customers will receive the complete source code.

Some parts of the software probably will use Open Source classes (GPL), e.g. the smarty template system or a pear class.

The actual code will be written by me.
Now I'm just interested if I'm allowed to sell the complete package (including GPL classes) with my own license (of course just for my own code).

I often read that if you use just one single line of GPL code the complete project must be released under GPL license, is this true?

AFAIK this is only true if you really use the code in the main program. I plan to use Open Source classes (which are independent from the main program), is this allowed?

Of course I want to support Open Source, I'll make donations for every sold license.

If you use the GPL, you must distribute the source code for your project. All of it, not just the GPL code you use.

That's not the problem, I'll distribute the complete source code (including my own code).

The problem is that I want to sell my software (my code + GPL classes) but I want to forbid to distribute my code.