Currently Google offers several options to chat:
- Google Talk Client (for Windows, written in C or C++)
- Google Talk Gadget (using Flash, runs on Web Browser, OS indipendent)
- Google Talk Web (integrated in Gmail)
Another nice implementation of online messengers is Meebo. It is a page, where you can login and use GTalk, MSN Messenger, Yahoo! Messenger and AIM. From a developer point of view it is interesting to see the capabilities of webpages...also because Meebo doesn't use Flash (also if it is hardly believable by looking at the UI) but it uses AJAX.