Windows/Unix: Free, open source instant messaging application Pidgin has just released a significant new update, chock full of bug fixes and some snazzy new features—among them more file transfer support, interface improvements, and improved customisation. For more details on the changes, check out the official ChangeLog. Pidgin is free, open source, works on all Windows and Unix platforms. If you're new to Pidgin, check out the ten must-have Pidgin plug-ins to get even more out of the killer cross-platform app. If you're a die-hard Pidgin user, let's hear why you love Pidgin in the comments.