PuTTY is a free implementation of SSH and Telnet for Windows and Unix platforms, along with an xterm terminal emulator.
minor feature: Security fix: a buffer overrun in the old-style SCP protocol when receiving the header of each file downloaded from the server is fixed. See vuln-pscp-sink-sscanf. Windows PuTTY now sets its process ACL more restrictively, in an attempt to defend against malicious other processes reading sensitive data out of its memory. Assorted other robustness fixes for crashes and memory leaks. We have started using Authenticode to sign our Windows executables and installer.