NewWorldStudio's OpenSim generator. It has bugs being still in beta, but Hey I have my own private World for 20 bucks with 100,000 or so prims as opposed to my region in SL which costs 40 bucks a month.
I still haven't figured out how to link my private world to other grids-NewWorldStudio's connectivity test shows it as public but since I use this region to experiment with mesh and physics...well maybe I don't want any visitors just yet. But I did learn about OAR files. More on that in a bit.
Speaking of mesh-finally a reason to learn a bit about Blender. I have used sculpties but found trying to do them in Blender a bit temperamental so ended up using one of the SL tools for doing sculpties. So on to mesh. I like doing mesh but one nut that I hadn't cracked in a couple days of scratching was how to how to get the textures to render in the dae files that Blender exports and SL and Open sim support. I had to grasp the concept of materials and also didn't notice the little check boxes in Blenders .dae export menu relating to exporting textures as well....duh.
One development I really in pleased with the Kitely. I had read about this company and its new business model and really low rates...so I plunked down money for their Bronze plan. Gives me a free region and costs 5 bucks a month. OK 5 bucks a month is definitely better than 40 bucks a month for what, an 8th of a region? Plus getting back to OAR files for just pennies I could upload an OAR file and even better can modify the terrain! How cool is that. That world is private for now. I can go public for 20 bucks a month...still a lot better than SL for the money.
Oh and it gets even better! Imagine my delight when I exported my world's OAR to my home machine and loaded it into OpenSim using NewWorldStudio and was able to watch my NWS World take shape in my viewer. How cool is that! Now if I could only use a common AV look across all Worlds...At any rate the picture shows me in the NWS version of my Kitely World. One giant sandbox. Presumably I can go the other way as well but haven't tried that yet.