UTR is an experiment in ways to build a federated encrypted chat system with a focus on deniability.
All communications are encrypted end to end. This is common, but not especially useful against surveillance. The difficult challenge is not to mask the content of a conversation between two people, but to make it impossible to determine that two people are even speaking to one another at all.
In order to achieve this goal UTR uses CouchDB to allow simple federation of UTR nodes. It then relies on many users of each of those nodes to mask conversation metadata. It will be obvious that a group of people are all using UTR, but it will be impossible for an observer (even a state level attacker) to determine which of those users are speaking to each other.