Additional
Information: Standards refer to the definitions and rules by which operating system perform different functions, like interfaces, libraries, filesystems, etc.
Standards Sites:
UNIX System Interface Tables UNIX System Interface Tables: These pages contain tables of all the Commands and System interfaces defined in UNIX 98, complete with an indication of their availability in UNIX 95, the ISO POSIX-1 standard, the ISO POSIX-2 standard, the ISO C standard, SVID3 and 4.3BSD. (Standards) http://www.unix-systems.org/apis.html
The Free Standards Group The Free Standards Group: A non-profit corporation to increase the use and acceptance of open source technologies through the application, development and promotion of standards. (Standards) http://www.freestandards.org/
Linux Standard Base Linux Standard Base: The goal of the Linux Standard Base (LSB) is to develop and promote a set of standards that will increase compatibility among Linux distributions and enable software applications to run on any compliant Linux system. (Standards) http://www.linuxbase.org/