Hyper-G

Hyper-G was built at the IICM at Graz University of Technology under Hermann Maurer, at roughly the same time the web was taking shape on the other side of the Alps. Its core idea parted ways with Berners-Lee's: links weren't embedded in documents but stored in a separate database on the server, and they ran both ways. Move or delete a document and the system knew exactly which links pointed at it and could fix them. Built-in search, access control and hierarchical collections came as standard — all things the web would later have to bolt on.

The clients were called Harmony (Unix) and Amadeus (Windows), and the server could also speak Gopher and HTTP. It wasn't enough. The web was trivial to set up and forgiving of sloppiness; Hyper-G demanded discipline. The project was later commercialised as Hyperwave and found a niche in corporate document management, while the 404 became a way of life.