Hello everyone. I'm looking around for opinions on a matter and, as I've been part of the Ubuntu community for quite some time, I figured I may as well ask here.

I'm working on an open-source PHP project, WebKernel (http://dev.mycustombb.com/). Despite the incredible amount of work for the project, I made the decision a while back to release it entirely under the GPL and worry about income later - perhaps by providing additional services and such.

However, PHP code can be a bit slow. I'm used to C speeds. Therefore, I decided to write some of the WebKernel code in C. But that would take even MORE work. So it hit me - most people won't need that extra speed. Businesses or other large websites may, but that's it. They will be able to afford to support the project by purchasing it (plus I'm a bit against businesses reaping the benefits of open source for their personal gain without providing any support whatsoever - I find it unethical).

So I thought I could provide the PHP functions as well as the C extension with the optimized functions for increased performance and additional benefits. The problem is - I don't want it to be proprietary. I strongly believe in free software. Only problem is - if I release it under the GPL, anyone can compile it for themselves. Businesses have no incentive to purchase it when they can just grab it from SVN and compile it.

What suggestions, if any, do you guys have? What are your opinions? How would I go about providing additional paid benefits without violating my ethics by making the extension closed-source? Are there other open source licenses you suggest? I thank everyone in advance for their input.