What software license should I release my code under?

Question

We're about to finish some free software and we're not sure what license we should release it under.

Here's the details:

1. The software is funded by several sponsors
2. The software is open source (edit: see comments)
3. The software will be free to download by the end-user
4. The software will be free to use and modify for personal and commercial use by the end-user
5. We want to retain ownership of the code
6. We don't want anyone else to distribute our product

What software license should we use?

Edit: this is a free php social arcade script. Something like a Kongregate.com clone.

Answer 1

Your criterion #6 means that the software will neither be Free (as defined by the Free Software Foundation) nor Open Source (as defined by the Open Source Initiative). This means that none of the licenses we are generally familiar with will apply, and so you probably need a custom license.

Write one based on criteria #3 through #6, or consult a lawyer.

One possible license:

You are free to download this software, and use and modify it for internal purposes. You may not redistribute it in any form.