Instantbird is an instant messaging client based on Mozilla XULRunner and the open source library libpurple created by the software developers of Pidgin . Over 250 add-ons allow user customization of, and addition of, features. Features Users can set their own user icon and display name. Several themes are included by default, including "Bubbles", which has the "Time Bubbles" feature of displaying time between messages, rather than timestamps within or adjacent to each message. Text copied from an Instantbird window is reformatted transparently to include timestamps in front of each message, in a feature called "Magic Copy". Instantbird includes an Add-ons system which allows additional protocol support such as LiveJournal's LJ Talk; there are over 250 additional add-ons available. Additional features available include "UI theming, language packs and dictionaries, developer tools and usability enhancements such as tab completion of nicknames, highlighting, colourising of buddies, and vertical tabs." The developers list some of their "favorite" add-ons as follows: "Colorize" buddy names, "Highlight" words in chats, "Tab Complete" nicknames and commands, "Reply to Nick" - doubleclick inserts name, "Show Nick" in color in multiuser chats, and "Vertical Tabs" to arrange conversations vertically. Conversation logging is enabled by default, but can be disabled. Supported protocols include: OSCAR (AIM/ICQ/MobileMe) Gadu-Gadu Novell GroupWise IRC Lotus Sametime MSNP (Microsoft Messenger service, commonly known as MSN, .NET, or Live) MySpaceIM Netsoul Odnoklassniki SIMPLE QQ Twitter XMPP (Google Talk, ...) YMSG (YIM) VKontakte