> you've pretty much given up your rights to you contribution

That's not true. With most CLAs, you retain all rights to your submission. You just give the maintainer a very generous license. I haven't seen a CLA that requires you to give up any rights to your own contribution.

If the maintainer decides to switch to a closed source license, you are free to fork and maintain an open source version with your changes.

This is the difference to copyright assignment. If you produce something as contractor or employee, usually whoever pays for your work owns it, and you can't go and publish your work under an open source license.

> the CLAs I've seen referenced generally only do one thing: give the entity who issued the CLA the rights to do pretty much whatever they want with your code (one key right is often the ability to go closed source or otherwise re-license the work without the author's permission) while usually granting the author no additional rights or consideration.

Indeed, but submitting a contribution under an MIT-style permissive license grants that entity a very similar set of rights.

The difference is that the author was aware of that grant at the time they contributed the code since it was implicit in the license. CLAs are often essentially a way to backdoor additional grants after the fact without the original author's permission.

How so? If anything the CLAs I've seen are much more explicit that your code may be distributed as part of a future closed-source version of the project than, say, the MIT license is.

With all of the well-known open source licenses, it's generally clear to the author up front what rights they are granting. With CLAs they are usually fuzzy by design: maybe the rights will be used to go closed source, maybe to sue anther entity, etc. (it generally depends on what's in the best interest of the entity who wrote the CLA) Sure, they're explicit in the sense that they say 'we can do pretty much anything we want down the road' because they have to... that's the point of the CLA: to grant the authoring entity the right to make decisions down the road without consulting those who contributed. Oracle is practically a textbook example of why this is usually a bad thing for developers/users.

> With all of the well-known open source licenses, it's generally clear to the author up front what rights they are granting. With CLAs they are usually fuzzy by design

Not my experience at all.

> Oracle is practically a textbook example of why this is usually a bad thing for developers/users.

What would have happened differently there if people had contributed under an MIT license instead of signing a CLA?