Other distributions

Nothing exists in a vacuum, this set of tools is only possible because others have previously made their work available. Below are a set of links to the distributions I have used here. Apologies if I forget any

Eric Young's SSLeay library. Also check out the SSLeay FAQ.
OpenSSL has replaced SSLeay.
rdist from USC.
Much of the code base is derrived from NetBSD which can be obtained from ftp://ftp.netbsd.org/pub/NetBSD/ or a mirror near you.