I plan to use bsddb/pybsddb in a commercial product written in python for windows and linux. I also plan to use py2exe.
Yet I am not sure about the legal implications. I have read that commercial products don't have to pay royalties as long as it is written in python. Is it true?
Python is released under the Python License. It's permissive, so you can use it with closed source commercial software.
The Oracle Berkeley DB is licensed under the Sleepycat License, which requires you to distribute the source of your code. You can't use it with closed source commercial software unless you buy a commercial license from Oracle.
There doesn't seem to be an explicit license for Pybsddb -- there is no license file in their source tree. It was at one time distributed with Python, so I would expect it to be a permissive license. Were you to buy a Berkeley DB license from Oracle, you could probably use it in closed source commercial software.
py2exe is licensed under the MIT License, another permissive license, so you can use that with closed source commercial software as well.
