PTPd is a complete implementation of the IEEE 1588 specification for a standard (non-boundary) clock. PTPd has been tested with and is known to work properly with other IEEE 1588 implementations. The source code for PTPd is freely available under a BSD-style license. According to the developers, PTPd is becoming an increasingly portable, interoperable, and stable IEEE 1588 implementation.
PTPd can run on most 32-bit or 64-bit, little- or big-endian processors. It does not require an FPU, so it is great for embedded processors. PTPd currently runs on Linux, uClinux, FreeBSD, and NetBSD. It should also be easy to port to other platforms.
PTPd is free. Everyone is welcome to use and contribute to PTPd.
Check it out here.
It is worth noting that this project has high rank on Sourceforge (4,6 out of 5 possible points).