Yesterday I found myself trying to figure how which version of Ruby was the latest on a particular date. I had trouble finding a resource with this information using google, so I posted a query to the ruby-talk forum, and Urabi Shyouhei posted a list derived from the ftp site.
In the interest of posterity, here's the list as of now:
| Ruby Version | Release Date (in Japanese time zone) |
| Ruby birthday | 02/24/1993 |
| 0.95 | 12/21/1995 |
| 1.0-961225 | 12/25/1996 |
| 1.0-971225 | 12/25/1997 |
| 1.1c0 | 07/17/1998 |
| 1.1c1 | 07/24/1998 |
| 1.1c2 | 08/11/1998 |
| 1.1c3 | 08/27/1998 |
| 1.1c4 | 09/03/1998 |
| 1.1c5 | 09/08/1998 |
| 1.1c6 | 10/05/1998 |
| 1.1c7 | 11/09/1998 |
| 1.1c8 | 11/19/1998 |
| 1.1c9 | 11/26/1998 |
| 1.2 | 12/25/1998 |
| 1.2.1 | 01/11/1999 |
| 1.2.1 | 01/12/1999 |
| 1.2.2 | 01/21/1999 |
| 1.2.3 | 02/16/1999 |
| 1.2.4 | 04/09/1999 |
| 1.2.5 | 04/13/1999 |
| 1.2.6 | 06/21/1999 |
| 1.4.0 | 08/13/1999 |
| 1.4.1 | 09/16/1999 |
| 1.4.2 | 09/17/1999 |
| 1.4.3 | 12/07/1999 |
| 1.4.4 | 04/14/2000 |
| 1.4.5 | 06/23/2000 |
| 1.4.6 | 08/16/2000 |
| 1.6.0 | 09/19/2000 |
| 1.6.1 | 09/27/2000 |
| 1.6.2 | 12/25/2000 |
| 1.6.3 | 03/20/2001 |
| 1.6.4 | 06/04/2001 |
| 1.6.5 | 09/19/2001 |
| 1.6.6 | 12/26/2001 |
| 1.6.7 | 03/01/2002 |
| 1.6.8 | 12/24/2002 |
| 1.8.0 | 08/04/2003 |
| 1.8.1 | 12/25/2003 |
| 1.8.2 | 12/25/2004 |
| 1.8.3 | 09/21/2005 |
| 1.8.4 | 12/24/2005 |
| 1.8.5 | 08/25/2006 |
| 1.8.5-p2 | 12/04/2006 |
| 1.8.5-p12 | 12/25/2006 |
| 1.8.5-p35 | 03/13/2007 |
| 1.8.6 | 03/13/2007 |
| 1.8.5-p52 | 06/09/2007 |
| 1.8.6-p36 | 06/09/2007 |
| 1.8.5-p113 | 09/23/2007 |
| 1.8.6-p110 | 09/23/2007 |
| 1.8.5-p114 | 10/04/2007 |
| 1.8.6-p111 | 10/04/2007 |
| 1.8.5-p115 | 03/03/2008 |
| 1.8.6-p114 | 03/03/2008 |
| 1.8.7 | 06/01/2008 |
| 1.8.7-p17 | 06/09/2008 |
| 1.8.5-p231 | 06/20/2008 |
| 1.8.6-p230 | 06/20/2008 |
| 1.8.7-p22 | 06/20/2008 |
| 1.8.6-p286 | 08/08/2008 |
| 1.8.7-p71 | 08/08/2008 |
| 1.8.6-p287 | 08/11/2008 |
| 1.8.7-p72 | 08/11/2008 |
| 1.9.1-p0 | 01/30/2009 |
| 1.8.6-p368 | 03/31/2009 |
| 1.8.7-p160 | 04/09/2009 |
| 1.9.1-p129 | 05/12/2009 |
| 1.8.6-p369 | 06/09/2009 |
| 1.8.7-p173 | 06/09/2009 |
| 1.8.7-p174 | 06/15/2009 |
| 1.9.1-p243 | 07/18/2009 |
| 1.8.6-p383 | 08/03/2009 |
| 1.8.7-p248 | 12/24/2009 |
| 1.9.1-p376 | 12/07/2009 |
| 1.8.6-p388 | 01/10/2010 |
| 1.8.7-p249 | 01/10/2010 |
| 1.9.1-p378 | 01/10/2010 |
| 1.8.6-p398 | 02/03/2010 |
| 1.8.6-p399 | 02/04/2010 |