IE9 has been released, and it finally includes the "nth-child" pseudo-selector in CSS! In the past, this has been done on a server side, or with javascript. Now we finally have simple CSS rules for rows in tables that highlight every even or odd row, and it works in every browser without any hacks.

tr:nth-child(odd) {
  background-color: #def;
}
tr:nth-child(even) {
  background-color: #fff;
}

Browser Release Date
IE1 April 16, 1995
IE2 November 22, 1995
IE3 August 13, 1996
IE4 September 15, 1997
IE5 March 18, 1999
IE6 August 27, 2001
IE7 October 18, 2006
IE8 March 19, 2009
IE9 March 14, 2011