Lately I've been hopping around various OpenSim-based grids to research which one(s) would be viable replacements given that Second Life may be irreversibly heading in the same direction that There went. So here's the rundown of the grids I've been to as of this writing:
- OpenLife: OpenLife was the first OpenSim-based grid to have an in-world currency, and that alone set up OpenLife as the first possible competitor to Second Life. Unfortunately, the OpenLife folks had forked OpenSim and chose not to release their changes back to the OpenSim community. While this is technically allowed because of OpenSim's BSD license, this act had basically turned OpenLife into a non-OpenSim grid.
- InWorldz: A currently small but growing OpenSim-derived grid similar to OpenLife. You're actually pretty likely to catch the founders and devs of this grid right from the first time you login to InWorldz, which is nice.
- OSGrid: The first non-Linden Lab grid I've ever been to, and without a doubt the biggest OpenSim-based grid. While it currently lacks an in-world currency(intentional because it's a non-profit grid), it's more or less ground zero for OpenSim development.
- ReactionGrid: And for something completely different, there's ReactionGrid. ReactionGrid is a lot like OSGrid, but with some very distinct differences: ReactionGrid has a solid revenue model by being an OpenSim grid hosting company, their OpenSim grids are hosted on Microsoft's Hyper-V technology, and grid operators are free to modify their grid server functionality if they wish. ReactionGrid is targeted at educators and businesses for collaboration, but there 's nothing stopping grid operators into purposing their grids for other uses.
This is by no means an exhaustive list or review of virtual worlds, just my opinions of those I've checked out so far. There's several others I'm interested in checking out, so stay tuned for a "Part 2" blog post in the near future.