Started somewhat earlier than 2005 (in some place it was mentioned hardware took a few months, and first news are about software after hardware is completed) and it's still going, last update from 3/29/2014: http://www.homebrewcpu.com/new_stuff.htm

Edit: the 2014 post mentions 10-year anniversary approching.

Second edit: this G+ post mentiones 10 years: https://plus.google.com/104192474935520300956/posts/D1cQEyof...