Thinstation is a free and open source Linux implementation of a thin client operating system.

An open source implementation is available, based on the udev mechanism.

Novell's Mono project, an open source implementation of the .

Mozilla supplies an open source reference implementation of the Weave server software, for example.

There exist several open source implementations of certificate authority software.

For the relay part there is also an open source implementation in Python, here.

An open source implementation was available from IBM starting in 2001.

There are plenty of good open source implementations to choose from.

So we have a large array now of open source implementations.

An open source Matlab implementation is freely available at the authors web page.