For Apple, there's quite a lot if you're willing to grovel through commits, but at the moment nothing is bigger than Clang/LLVM -- a large chunk of the core team is directly employed by Apple, and with FreeBSD 10 Clang is directly incorporated into the core system. Apple has, at various times, employed other FreeBSD core committers directly. They very quietly have done a lot to support the project.

Sony, IIRC, employed some Japanese committers who were working on ACPI at one point.