OpenSimWorld is the directory of 3D Virtual Worlds based on OpenSimulator and connected through the HyperGrid. Learn More

Want your own doomsday server? Imagine having all of wikipedia downloaded to a hard drive with a program that can search and display articles. Kiwix for desktop (freeware) can do it. It even has download links under 'All Files' to d/l the wikipedia database for you making it painless. Not only that but you can download a bunch of other wiki's too. Imagine having maps of the world. Or a doomsday prep wiki. TedTalk videos. Audio books wiki. etc.
https://kiwix.org/en/applications/ - by the way, it runs on linux/mac/windows/android.