(Second) Life Like

Among the virtual worlds out there, there's a number of grids that share a lot more than being accessible with the same client softwares (Viewers) - they are based on the server code developed by the Opensim project, which in short reverse-engineered the SL server code after LL open-sourced their viewer code ... so they are basically compatible with each other and Second Life.

With significant limitations though, they all have the feel of what SL must have been like a few years ago, before I joined: sim-crossing is a pain, physics are poor, scripting is limited, no search, most have no currency, and so on ...

But still, thanks to free upload they are a alternative to the beta grid for testing animations before uploading them to SL, or sculpt textures etc. - which is what the standalone version of the Opensim server software is extremely useful for. It installs your personal region on your PC, which makes anything quite fast and lagfree (unless you pack your region with scripts that lead to errors which will make things go bad). It's also possible to host your region(s) on the net for public access, or connect it to existing grids, something I can see great potential in.

Had I written this post a week ago I would have mentioned the Openlife grid as the most important of these alternative public grids out there. Only, Openlife has dropped out of the Opensim project recently to go proprietary, locking out all other viewers than their own, pissing off users of the various existing viewers including Second Inventory, a backup tool that allows creators to transfer their content to other grids. 

Hence they are not on this current list of Opensim grids: http://opensimulator.org/wiki/Grid_List. (And hence I removed it from my list of grids to visit on a frequent basis.)

Advantages of Opensim over SL : a region in an Opensim region can support 45000 prims - compared to 15000 in SL; prims can have sizes larger than in Second Life; end of list.

At some point interoperability of grids is an aim of the project, but this will need a lot of sorting out of how to handle assets when crossing grids beforehand.