PGO is pretty new, and it's turned on for the current builds of Firefox 3.1. I'm guessing it wasn't enabled by Mozilla initially for the usual reasons of compl

PGO is pretty new, and it's turned on for the current builds of Firefox 3.1. I'm guessing it wasn't enabled by Mozilla initially for the usual reasons of complex packaging problems and low manpower for the Linux version. Distribution packagers generally aren't that knowledgeable about what they package, but that probably isn't what's wrong in the specific case of Firefox, which gets a lot of attention. For Firefox, it's probably the fact that Mozilla has very specific software requirements, and distributors have been burned (http://www.0xdeadbeef.com/weblog/?p=368 http://www.0xdeadbeef.com/weblog/?p=368) in the past by ignoring them. So... distributions generally don't do much to change what they distribute as Firefox.