- Official test suites for LSB from the Linux Foundation that are used in certification for conformance to the standard. Most of the LSB Core tests are based on the tests from The Open Group.
- Linux Test Project (LTP) is a joint project started by SGI and maintained by IBM. The goal of the project is to deliver test suites to the open source community that validate the reliability, robustness, and stability of Linux. The LTP testsuite contains a collection of tools for testing the Linux kernel and related features.
- Open POSIX Test Suite is a project supported by Intel on creating an open test suite with the goal of performing conformance, functional, stress, and performance testing of the functions described in the IEEE Std 1003.1-2001 System Interfaces specification (POSIX.1). The NPTL Tests and Trace project has made significant contribution to OpenPosix tests.
- The developers of the glibc library use their own tests distributed over the source code tree of the library. These tests are used for regression testing and do not officially support any standards.