Fascinating introduction to early hyperlinks: there were 'linkbases' (storing links separately from the content), they weren't 1:1 (one link could point to multiple destinations) and had gossip protocols to update on other servers!
https://moocs.southampton.ac.uk/websci/2014/02/21/open-hypermedia-web/ https://edshare.soton.ac.uk/6158/1/Open_Hypermedia.pptx