Ever hear of Macports or Homebrew? They have almost everything I need, usually with the most up to date version. No 2 year old stale packages like Debian.
Edit: Don't presume this for everyone.
Edit: Don't presume this for everyone.
That's really the core problem; on linux, all of the software on my machine is from the open source ecosystem and it tends to follow the unix patterns and work well together. On OS X, it was a mix of open source and what comes out of Jobs' Garden. It also meant that ports to OS X package systems were always behind linux.
I can understand your trepidation when using XCode to build things, but in reality I've never had any trouble using Homebrew. The packages are updated often, and if you want to contribute something, it's super easy (I've done it myself), since they're on Github.
For example, epoll is not supported (and I haven't seen a good epoll wrapper for kqueue)