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.
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.
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.