Which type of open source license do you prefer?

It's the age-old debate among open source enthusiasts—both developers and users alike: Which license to choose? For developers, the decision revolves around what kind of control they are willing to release to anyone wanting to modify the developer's code. For the user, the question is more about philosophy.

Copyleft licenses such as the GPL require that derivative works carry the same protections as the original project, and that the source code be provided for derivatives created. Permissive licenses generally only concern themselves with the licensing of the original program.

Regardless of what your role is in the open source community, we want to know: Which type of license do you prefer, and why? Let us know your choice, and tell us why in the comments below.