[gillianseed]

FreeBSD has had a long outspoken goal of not relying on GPL in the base system, an ideological choice. The transition to clang/llvm has also been very long and will (if everything goes as planned) be finalized in FreeBSD 10.

https://wiki.freebsd.org/GPLinBase

Apple (as they would not accept GPLv3) was stuck with shipping the very old GCC 4.2.1, also Apple wanted to be able to incorporate the compiler toolchain into their proprietary solutions like XCode, something GPL obviously won't allow. Hence funding LLVM while starting work on Clang made sense for them, but again not a choice made (purely) on technological merits.

[vor_]

> Hence funding LLVM while starting work on Clang made sense for them, but again not a choice made (purely) on technological merits.

I think it's inaccurate to portray the move away from GCC as simply political with happy side effects, though avoiding the GPL3 was certainly a prime motivation. Greg Parker has stated on Apple developer mailing lists that the adoption of Clang/LLVM has allowed them to rapidly improve the Objective-C language, and that there are more Apple employees working on the language and compiler today than 10 years ago.