Massively

If you read that last line with a bit of an undefined but vaguely Eastern European accent, well, METAbolt can take you one better. They have integrated text translation, so you can interject random comments in German, say, while a poor lonely soul tries to get a complete stranger to remove all the clothes from her avatar. Unfortunately, the translation goes only one way.

Though saved Landmarks were not visible, METAbolt claims to completely support teleports, land management, and most other things you might do that do not require the ability to see and manipulate the graphical world. That said, it's probable that the vast majority of METAbolt users want it for the ability to put lots and lots of avatars online at once without overstressing their computers. As a lightweight text client, having a dozen avatars online at once puts less strain on your system than loading a document in Microsoft Word.

Being still in beta -- not quit gone gold, they refer to the client as "gone white" -- some features are still incomplete or broken. Inventories are not reliable. Modifying your profile results in a runtime exception. Grouping doesn't seem to work, nor do fat friends lists. It also relies upon Microsoft-specific technologies such as ASP.NET, a decision that locks them out of OSX and Linux, both platforms on which Second Life runs.

As a chat client, METAbolt doesn't have the rich support of text-based chat that you might see in AIM or IRC. Still, if you need to have a presence in Second Life even in places you cannot run the graphical client -- or just have a pressing need to log in several alts/bots at one time -- METAbolt might be worth a look. We've been using it for days now, and keeping in touch with people online without having to load up the full graphical client can be incredibly useful.