What year did CERN place the Web in the public domain?

1993 → tub · beam.

On 30 April 1993, CERN released the World Wide Web's software into the public domain, royalty-free — a decision that let anyone build on it without asking permission or paying a licence, and arguably the single choice that let the Web explode rather than fragment into competing paid systems. That same year the Mosaic browser, built at the University of Illinois's NCSA by a team including Marc Andreessen, made the Web graphical and easy — showing images inline with text — and kicked off the browser boom that became Netscape. Peg 19 · 93 → tub · beam: a beam of light striking a tub.