Editing 1991 in science (section)

==Computer science==
* February 26 – [[Tim Berners-Lee]] introduces [[WorldWideWeb]] (the first [[web browser]]), and a [[WYSIWYG]] [[HTML editor]].
* May 14 – [[Nicola Pellow]], an intern working under the direction of Berners-Lee, introduces [[Line Mode Browser]], the first cross-platform web browser.
* June 5 – [[Phil Zimmermann]] posts the first [[Pretty Good Privacy]] (PGP) [[data encryption]] [[computer program|program]].<ref>{{cite web|url=http://www.philzimmermann.com/EN/news/PGP_10thAnniversary.html|title=PGP Marks 10th Anniversary|first=Philip|last=Zimmermann|date=2001-06-05|accessdate=2012-01-28|archive-date=2011-05-14|archive-url=https://web.archive.org/web/20110514200112/http://www.philzimmermann.com/EN/news/PGP_10thAnniversary.html|url-status=dead}}</ref>
* June 23 – The [[video game]] ''[[Sonic the Hedgehog (1991 video game)|Sonic the Hedgehog]]'' is first released, propelling the [[Sega Genesis]] [[History of video game consoles (fourth generation)|16-bit console]] into mass popularity.
* August 6 – The first [[website]] goes online at [[CERN]].<ref>{{cite web|title=Welcome to info.cern.ch, the website of the world's first-ever web server|publisher=CERN|url=http://info.cern.ch/|accessdate=25 May 2008|archiveurl=https://web.archive.org/web/20080527152659/http://info.cern.ch/|archivedate=27 May 2008|url-status=live}}</ref><ref>{{cite web|title=World Wide Web—Archive of world's first website|publisher=World Wide Web Consortium|url=http://www.w3.org/History/19921103-hypertext/hypertext/WWW/TheProject.html|accessdate=25 May 2008}}</ref><ref>{{cite web|title=World Wide Web—First mentioned on USENET|date=6 August 1991|url=http://groups.google.co.uk/group/alt.hypertext/msg/06dad279804cb3ba?dmode=source&hl=en|accessdate=25 May 2008|archiveurl=https://web.archive.org/web/20080512015304/http://groups.google.co.uk/group/alt.hypertext/msg/06dad279804cb3ba?dmode=source&hl=en|archivedate=12 May 2008|url-status=dead}}</ref><ref>{{cite web|title=The original post to alt.hypertalk describing the WorldWideWeb Project|work=[[Google Groups]]|date=9 August 1991|url =https://groups.google.com/group/comp.archives/browse_thread/thread/9fb079523583d42/37bb6783d03a3b0d?lnk=st&q=&rnum=2&hl=en#37bb6783d03a3b0d|accessdate=25 May 2008}}</ref>
* The [[Trojan Room coffee pot]] at the [[Computer Laboratory, University of Cambridge]], England, inspires the first [[webcam]].
* October - [[Apple Inc.|Apple]] releases the [[PowerBook]] [[laptop computer]].