You do have a point that its rock solid but I reciently took a course in writting system level code for various unixes and the main problem i have with Solaris is that its not fully posix complient. Usually if you write a program you dont want all sorts of special cases based on the OS and unfortunatly i did not find this with solaris. Some of the libraries had functions that didnt have the same prototypes as their posix bretheren did and at times it was completely missing functions from the SYSV library assuming it had it at all. Im not gonna say its not a good platform because its definitly stable but you cant expect to write portable c code for unix and expect it to work on solaris. If you want something to work on solaris design it for solaris in the first place.