hmm. What uriel may be saying is that a lot of open source software, allegedly portable, is really only "portable" to different Linux distros. I have seen this more and more in recent years. Just take any of a dozen chunks of "portable" code and try to build it on mac osx, for example. All too often, if tails.
But you fairly quickly learn what these Linuxisms are, and how to undo them. I own a Mac, and deal with this on a regular basis. Most of the time I find the most non-portable part of the whole is autoconf/configure. Somewhat ironic, don't you think? In my view, autoconf has become a caricature of itself.
One reason why I like to keep a Solaris machine around is to have a completely non-GNU compiler toolchain handy. That makes it easy to weed this nonsense out. POSIX may be braindead in a lot of ways, but if used with common sense it does allow for widely portable code. For the vast majority of applications software, there really isn't any need for autoconf in this day and age.
It is also the case that some non-Linux OSes have felt pressure to add Linux-like features ...
Add? Or emulate. FreeBSD and Solaris both support runtime emulation of Linux. This doesn't mean Linux is taking over the core OS (thank God). I don't have a problem with anyone providing runtime ABI compatibility for Linux applications, since it doesn't infect the core OS environment.
--lyndon
