[eliben]

That's not entirely true. libc++ works on Linux too. In fact, Google's PNaCl has experimental libc++ support that's completely cross-platform.

[pmelendez]

And in windows too http://llvm.org/builds/

[fedvasu]

yeah right. It is beta-quality unfit for pre-packaging in distro's. ABI incompatible with libstdcxx and deliberately OS X only. (It works sure (i mean kinda) no one is actually a linux port developer or maintainer not yet)