These features are new in beta 0.59 (released 2007-01-24):

• PuTTY can now connect to local serial ports as well as making network connections.
• Windows PuTTY now supports "local proxying", where a network connection is replaced by a local command. (Unix PuTTY has supported this since it was first released in 0.54.) Also, Plink has gained a "-nc" mode where the primary channel is replaced by an SSH tunnel, which makes it particularly useful as the local command to run.
• Improved speed of SSH on Windows (particularly SSH-2 key exchange and public-key authentication).
• Improved SFTP throughput.
• Various cryptographic improvements in SSH-2, including SDCTR cipher modes, a workaround for a weakness in CBC cipher modes, and Diffie-Hellman group exchange with SHA-256.
• Support for the Arcfour cipher in SSH-2.
• Support for sending terminal modes in SSH.
• When Pageant is running and an SSH key is specified in the configuration, PuTTY will now only try Pageant authentication with that key. This gets round a problem where some servers would only allow a limited number of keys to be offered before disconnecting.
• Support for SSH-2 password expiry mechanisms, and various other improvements and bugfixes in authentication.
• A change to the SSH-2 password camouflage mechanism in 0.58 upset some Cisco servers, so we have reverted to the old method.
• The Windows version now comes with documentation in HTML Help format. (Windows Vista does not support the older WinHelp format. However, we still provide documentation in that format, since Win95 does not support HTML Help.)
• On Windows, when pasting as RTF, attributes of the selection such as colours and formatting are also pasted.
• Ability to configure font quality on Windows (including antialiasing and ClearType).
• The terminal is now restored to a sensible state when reusing a window to restart a session.
• We now support an escape sequence invented by xterm which lets the server clear the scrollback (CSI 3 J). This is useful for applications such as terminal locking programs.
• Improvements to the Unix port:
  • now compiles cleanly with GCC 4
  • now has a configure script, and should be portable to more platforms
• Bug fix: 0.58 utterly failed to run on some installations of Windows XP.
• Bug fix: PSCP and PSFTP now support large files (greater than 4 gigabytes), provided the underlying operating system does too.
• Bug fix: PSFTP (and PSCP) sometimes ran slowly and consumed lots of CPU when started directly from Windows Explorer.
• Bug fix: font linking (the automatic use of other fonts on the system to provide Unicode characters not present in the selected one) should now work again on Windows, after being broken in 0.58. (However, it unfortunately still won't work for Arabic and other right-to-left text.)
• Bug fix: if the remote server saturated PuTTY with data, PuTTY could become unresponsive.
• Bug fix: certain large clipboard operations could cause PuTTY to crash.
• Bug fix: SSH-1 connections tended to crash, particularly when using port forwarding.
• Bug fix: SSH Tectia Server would reject SSH-2 tunnels from PuTTY due to a malformed request.
• Bug fix: SSH-2 login banner messages were being dropped silently under some circumstances.
• Bug fix: the cursor could end up in the wrong place when a server-side application used the alternate screen.
• Bug fix: on Windows, PuTTY now tries harder to find a suitable place to store its random seed file PUTTY.RND (previously it was tending to end up in C: or C:WINDOWS).
• Bug fix: IPv6 should now work on Windows Vista.
• Numerous other bugfixes, as usual.