What License To Use?....

We will be releasing a new open source project but we are having trouble trying to determine what license to use. I am hoping someone can help here.

Interesting - I have rudimentary exposure to open source licensing.  I do believe what you are talking about is entirely possible however.  Take a look at DOT NET Nuke - its based on Dot Net (not open source) but is open source itself.  I don't think they use the GPL.  Maybe try looking at the [ Open Source Initiative ] site for more help with this.  Or just copy the license that dotnetnuke is using.

Release "SomeBuilder" as freeware, allowing people to use the tools/API/whatever as part of other applications. Freeware was designed to allow people to use/distribute a closed-source program. Shareware or donationware licenses would also work, but they include the expectation that the programmer (you) should get money.

There's no standard freeware license, but you can find many examples by Googling

There shouldn't be any license compatibility issues, since the derivative program is the one that's GPL'd.

What license is "SomeBuilder" released under?

 EDIT: previous comment makes sense. I didn't realize that "SomeBuilder" was also built by you, I thought it was an external package you were using.