libsrs2 is the next generation SRS library from the original designer of SRS. It implements the Sender Rewriting Scheme, a part of the SPF/SRS protocol pair. Libsrs2 has been written from an entirely clean codebase with compliance, speed and versatility in mind. It is platform independent and has no external dependencies. It is thread-safe and heap-safe, and is suitable for large scale applications and embedded systems and can operate without many standard system facilities.