Saw this a day or two ago on lXer and look which OS is top of the pile! Much deserved i would say! Now if only we could get to the top 5 Operating Systems full stop we would be laughing! 
http://p-quinn.com/entries/report/report-the-alternative-os-my-top-5
A nice article, although I wonder if the author considers Linux to be an āalternativeā operating system or not.
A couple of small quibbles ā although development of the BeBox started in 1991 it didnāt run BeOS until 1995 or so, and Haiku development started in 2001, not 2003. The earliest commit in the Haiku git repository goes back to 2002 although I believe this was an import from a CVS repository (which was imported into Subversion and then later transferred into git) that went back even further.
Well the site seems to focus primarily on Linux so id imagine he doesnāt regard it as an alternative OS otherwise it would be on the list and by the looks of it he got all his info off the wiki page which gives 2003 as the date that the project switched from OpenBeOS to Haiku