* Kerberos/GSSAPI authentication in SSH-2.
* Local X11 authorisation support on Windows. (Unix already had it, of course.)
* Support for non-fixed-width fonts on Windows.
* GTK 2 support on Unix.
* Specifying the logical host name independently of the physical network address to connect to.
* Crypto and flow control optimisations.
* Support for the zlib@openssh.com SSH-2 compression method.
* Support for new Windows 7 UI features: Aero resizing and jump lists.
* Support for OpenSSH AES-encrypted private key files in PuTTYgen.
* Bug fix: handles OpenSSH private keys with primes in either order.
* Bug fix: corruption of port forwarding is fixed (we think).
* Bug fix: various crashes and hangs when exiting on failure,
* Bug fix: hang in the serial back end on Windows.
* Bug fix: Windows clipboard is now read asynchronously, in case of deadlock due to the clipboard owner being at the far end of the same PuTTY's network connection (either via X forwarding or via tunnelled rdesktop).