I find it interesting in light of the licensing debates between GCC and Clang. GNU goes to great lengths to ensure that anyone modifying or extending GCC is legally obliged to release their changes -- including technical design decisions that actually make GCC's code difficult to reuse even in GPL-compatible projects. Clang is under a permissive license, so Sony has no obligation to release their changes, but apparently they are anyway.

I realize that GCC's policies were actually important for getting Next to release their Objective C code in the 90's, but it seems like times have changed. Companies have learned that keeping their code a secret actually isn't a huge competitive advantage whereas releasing it has a lot of real benefits (such as reduced maintenance cost). It's always better to have people doing the right thing because it's in their interests rather than because you forced them to.