Several pieces of third-party software incorporate parts of the
PuTTY code, or augment PuTTY in other ways, to provide facilities not
available from PuTTY itself. We list some of them here, with no
recommendation implied. We have no control over this code, so we
can't vouch for either its quality or its security.
Software based on PuTTY's code
These projects include actual code from some version of PuTTY.
Safe Passage, an alternative
to PuTTY's dynamic port forwarding which doesn't require SOCKS
support in your client applications (it seems to install itself
somehow at the Windows networking level). Based on the PuTTY code.
Commercial, but cheap.
TuTTY, a fork with several extra features, including a
serial backend
(this dates from before PuTTY had its own)
PieTTY, a fork with CJK/transparency/URL recognition etc (no source?)
KiTTY, a (Windows-only) fork with several features including
storing your password, minimising to the
system tray,
and automatically sending a command (as if typed at the keyboard)
after successful session startup.