[ifcologne]

FoundationDB was a closed-source database. It was never open-source.

They had only open-sourced the SQL-Layer on top of their key/value store and it's still available on Github. The reason: They build it based on open-source code

When someone deletes a public repository on Github, one fork remains as the new master. (Here's FoundationDB's SQL-Layer: https://github.com/louisrli/sql-layer)

So: RethinkDB will stay, even if someone tries to pull the plug. Just fork them on Github. :)