[progmetaldev]

You might be surprised. Unless you are dealing with clients that have been burned by software licensing, or have attorneys knowledgeable in software patent/licensing law, you could charge clients for building software and release it as GPL. You then also provide the setup of that software, which you can include in the total cost. There is lots of GPL software out there, but not many people that understand how to setup or support that software. It is very possible to make a good living off the setup and support of GPL and other open source software.

If you don't feel right for open sourcing software you wrote for someone else, you could always offer your client a discount to let you open source the software. There are quite a few companies that now make their money supporting open source software, even when they aren't writing it themselves. I've done this myself, and I think it's a lucrative business model that still gives everyone involved freedom.