Is it legal to branch an open-source project that has gone commercial?

Question

I have some open-source apps that use a component that was open-source but is no longer so, with its CodePlex repository and project page removed. Do I have legal right to create a branch from the last available source code snapshot available before the project was removed?

Answer 1

If you have source code that was published under an open source license, you can do whatever you want with it as long as it complies with the terms under which you obtained it. With open source, this almost always includes creating a a fork.

Answer 2

It depends on the license, but GPL2 is fair game - the Linux kernel did it with OSS3 for example.

Answer 3

IANAL but look at how Wine and Cedega branched.

Formerly known as WineX, Cedega represents a fork from the last MIT-licensed version of Wine in 2002

Answer 4

The fact that they used a different license on subsequent versions of their software doesn't change the license for the version you have a copy of. At least not in most licenses currently used for open-source.

I suppose there could be a license that reserves the right of revocability, but that probably wouldn't be kosher as an OS license according to OSI.

I was working at some companies in the late 1990's when a lot of business people discovered that open-source was a good PR strategy. They told me to open-source their product, and I felt obliged to make them understand (though it took several tries) that they couldn't "un-open-source" that software the next week.