[flagged]
They follow the licenses.
Apple has paid developers to work on WebKit, Clamg/LLVM, and CUPS. That’s off the top of my head. All open source. All available to you. I remember reading how they contributed fixes to a huge number of packages in the OSS ecosystem when working to get POSIX certification as they fixed issues.
They released Swift as open source when they didn’t need to, and keep opening more libraries for it as they work to reimplement foundation.
You may not like Apple, but they’re not a leech. They give back.
As well as Apache Cassandra before they switched to FoundationDB which is still open-source and maintained.
They just tied it to SQLite whereas in the past it was a general ORM.