Not worked with them directly, but have followed the pg-hackers mailing list and they are have a bunch of contributions back to core Postgres, and have some cor

Not worked with them directly, but have followed the pg-hackers mailing list and they are have a bunch of contributions back to core Postgres, and have some core maintainers on staff. They seem very open with everything they do, as opposed to EDB, which do contribute back but also have a bunch of closed source tools and their own closed source Postgres fork.