It is much easier as a Google employee to publish open source projects under Google's copyright rather than getting them to grant the copyright to you.

To have Google give you (the Google employee) full copyright of projects you work on while at Google, you need to go through a committee[0] that reviews the project to make sure it doesn't collide with some other project Google already is working on. As this is really hard to do for many projects, it's easier to just let Google keep copyright ownership of it and have it opensource under them.

[0] https://opensource.google.com/docs/iarc/

Thanks for info and the link!

I would guess these types are projects are ones done in 20% time at google.

That guy who blasted Google on HN a while back (not the memo guy) said that since new management has come in over the last few years, 20% time is as good as dead. I couldn't find a link, sorry.

Guessing these were made in an employees 20% time or something similar, they felt it would be useful to publish them but not take flak when it has bugs or they don’t actually support it.

Because Google owns the source code per the employee contact.