The very beginning of SL can be found on rec.games.go, where there were at a period several posts about 'the ultimate Go site'. One of the results of this discussion was to set up a mailing list (GoWebmasters@onelist.com). The discussion about what to put on such a site and how it could be managed lasted a few weeks but eventually dropped off.
A while afterwards, Arno mentioned that a Wiki may be a good basis to present SL on. We looked at the wikis out there and there was a discussion about how/what and a refinement of our ideas and in May 2000 Arno had set up a wiki which we used to discuss the GoWiki. (The name Sensei's Library just happened to be used once and then stuck with us.)
The Gowiki as you see it today is the result of me prodding and suggesting and being awkward, with Arno doing all the hard work - Arno ended up doing the vast majority of the coding. In the summer of 2000 we defined most of the basic ways we thought the wiki should allow navigating and editing and created the diagram interpreting code.
In September 2000, the Gowiki as you see it now was started, although it was empty to begin with, and the Path function wasn't there yet.
We started to fill SL with various pages to set up a starting structure and to have some content to lure contributors with, and in mid-Novermber, the GoWebmasters mailing list was asked to have a look at SL as it was. The first contributions from 'real' users therefore date from November 2000.
I will have to look for the date, but SL was then also advertised on the newsgroup rec.games.go a bit later, in January 2001.
Since then, the number of contributors has grown slowly but steadily.
And the rest, as they say, is history.
-- Morten Pahle
Page number milestones:
- 1000 pages, August 28 2001 : Gokyo Shumyo, Section 1, Problem 49 / Solution, created by Dieter Verhofstadt
- 2000 pages, July 9 2002 : Beginner Exercise 67, created by unkx80
- 3000 pages, September 17 2002 : Takeda Hiroyoshi, created by Charles Matthews
- 4000 pages, November 14 2002 : Inoue Ichiro, created by Charles Matthews
- 5000 pages, January 3, 2003 : Kyu Exercise 4 / Attempts, created by yjlim
- 6000 pages, April 18, 2003 : Up and Down, created by MAsterdam
- 7000 pages, July 16, 2003 : Unusual Materials, created by StFiend
- 8000 pages, December 27, 2003 : Beginner Exercise 162 / Solution, created by Hikaru79
- 9000 pages, June (?) 2004
- 10,000 pages, November 11, 2004: Ing Timing, created by Robert Pauli
- 12,000 pages, September 28, 2005: BQMRJ000, created by Robert Jasiek
- 13,000 pages, April or May 2006
- 14,000 pages, October 2006
- 15,000 pages, May 2007
- 16,000 pages, December 2007
- 17,000 pages, June 2008
- 18,000 pages, 2nd (?) February 2009
- 19,000 pages, July 28, 2009: RTG Problem 57 / Solution, created by unkx80
- 20,000 pages, May 28, 2010: Dave Sigaty / 20000th Page, created by Dave Sigaty
- 21,000 pages, August or September 2012
- 22,000 pages, February 2016
- 23,000 pages, July 2021
- 24,000 pages, September 2021
- 25,000 pages, July 2022
To see what Sensei's Library looked like in February 2001 - http://web.archive.org/web/20010202054000/http://senseis.xmp.net/