Mosaic was the first popular graphical WebBrowser, written by MarcAndreessen in 1993, and sadly devoid of the wiki-like features (particularly, integrated editing of pages) that TimBernersLee, TedNelson and VannevarBush would have expected.
The moral of the story: If you don't make a GUI for it, someone else will.
Except... TimBernersLee's first browser did have a GUI. The only problem was, it was only for NeXT workstations.
Mosaic turned 10 years old on April 22, 2003.
The name Mozilla supposedly means "Mosaic killer"...