Yes, I agree with Adam. According to my research (and memory) Fruit 2.2.1 was leading the ratinglists in December 2005. It was not before 2006 that all these Fruit versions started to appear and also Toga made its presence in 2006. However in spring 2006 an engine called Rybka was introduced......Fruit 05/11/03 was the strongest Fruit that existed in December 2005. But, it does not appear to have been available until 2007. Fruit 2.2.1 was the strongest version available to the community in December 2005.
Following a period with a close battele between Fruit 2.2.1, Fritz 9 and Hiarcs 10 Rybka made a huge step forward. If you take a look at the Ratinghistory for the CSS list you'll se that in the middle of March 2006 Fruit was leading the list with 2810 in rating and then in the end of March Rybka 1.1 32 bit was leading with 2906!!
http://www.computerschach.de/index.php? ... Itemid=246
Almost an increase of 100 points....That happends only very rare.
Regards
Per