What was Chaosnet? Two-Bit History digs into this question in searching the configuration of DNS.

Why might a DNS record have a class other than “internet”? What would that even mean? How do you search for a host that isn’t on the internet?

In addition to IN, DNS records can have the HS class or the CH class. The CH class is reserved for something called Chaosnet.

Chaosnet was developed in the 1970s by researchers at the MIT Artificial Intelligence Lab. It was created as a part of a larger effort to design and build a machine that could run the Lisp programming language more efficiently than a general-purpose computer.

The problem with Lisp was that it could be slow. In the late 1970s, a group of MIT Artificial Intelligence Lab researchers decided to address these problems by building machines specifically designed to run Lisp programs. These “Lisp machines” had more memory and a compact instruction set better-suited to Lisp.

The processors would share access to a file system and to devices like printers via a high-speed local network “with completely distributed control.” That network was Chaosnet.

You can read more in the article here and on the Chaosnet wiki.