Tlon is the corporate vehicle of the open-source Urbit software stack (urbit.org).
Urbit is a clean-slate reimplementation of the whole system software stack. On the bottom it's a replacement of the lambda calculus, in the middle it's a new functional programming language, on top it's a purely functional network operating system in which address space is property.
Tlon owns approximately half of the entire address-space on the Urbit network.
The goal is to create a new layer over the Internet the way the Internet layered over the PSTN. This layer can also earn adoption by providing Internet services. On the Internet, your Urbit ship is a general-purpose personal cloud computer which replaces the 47 special-purpose cloud silos you're currently using.
Tlon's mission is to contribute to the development of Urbit, to provide hosting services for Urbit ships, and to develop other possible business applications on top of the Urbit stack.