https://opensource.oracle.com/ (almost endless list)
But then they have take FLOSS projects and abandoned them, see OOo for instance:
https://en.wikipedia.org/wiki/Apache_OpenOffice#/media/File:...
https://blogs.oracle.com/linux/post/oracle-is-the-1-contribu...
XFS is really important for (their) database performance, so quite a lot comes out of Oracle for it. You might also know that btrfs began at Oracle.
https://www.google.com/search?q=oracle+blog+xfs
https://en.wikipedia.org/wiki/Btrfs
"Chris Mason, an engineer working on ReiserFS for SUSE at the time, joined Oracle later that year and began work on a new file system based on these B-trees."
I see this argument a lot, but I'm not sure how it detracts from their continued development. Oracle funds many engineers working on OSS and, despite having CLAs in place, retain the permissive license for most of them. In some cases they've acquired closed source software and made it open source (e.g., JRockit stuff). They're a major contributor to OSS.
It would be hubris if they tried to then take the moral high ground.