[valley_guy_12]

The web could have plausibly existed as early as FTP did. Which would have been 1972. Plenty of documents from that era had URL-like manual links of the form "pub/foo/bar.txt at MIT-AI", and many FTP servers supported anonymous login and were fast enough for real-time text document retrieval.

It is kind of embarrassing that it took 20 years to invent URLs and browsers.

[rjsw]

I wrote a networked hypertext system in 1985 but it used a binary "page" format to save bandwidth. The GUI used was GEM.

Another road not taken could have been to define a rich text format in ASN.1 and build a browser on top of the OSI network stack.

[ngcc_hk]

Phd needed to understand Asn.1 and … osi network stack. Good luck.