Since the opensourcing of the client side of Second Life there have been some more or less interesting projects going on in forking the browser or developing it into something better/more.
Some projects especially are worth mentioning there:
- ShoopedLife. This is basically a viewer that people use who are concerned about their anonimity (haha!). Well, the original client sends some kind of information about your hardware (seems to be the MAC-address of your network interface and the primary partition ID of your first hard disk drive) to the LL server to identify your computer regardless of your login, so that they can permban you if necessary. ShoopedLife circumvents this by sending just some random address instead, so that you can still login even if banned. Griefers love this client very much because it allows them to still login in such a case. Of course, you cannot login with the old account but are then able to make just a new account with trash mail address since Linden Lab will be unable to identify your computer.
- realXtend viewer. The target audience of this project is much broader than ShoopedLife. realXtend is a fork of Second Life, so to speak, it has a Second Life compatibility mode builtin but also can connect to much more in graphic terms advanced OpenSim-grids, which is it real use for now. At the moment it's only available under Windows, Linux and Macintosh are going to follow later. Although still in the beginning, this project already shows much promise and is for sure going to be a real competitor for Second Life.
- RestrainedLife viewer. That's for the BDSM-lovers under the players. It let's the master control certain aspects of the subs viewer, e.g. attachments cannot be taken off anymore, communication can be blocked of the subs and other aspects can be controlled by the master, too. So - not everybody's kind of viewer, but for sure subs are going to love it to be in control of their master, if they bought the right in world tools for it, that is. This viewer is for sure not for the normal audience of Second Life.