Thanks to a software review in the latest (November 2006) issue of Project Manager Today, we learn that UK AEC vendor BuildOnline:
"markets a ‘project extranet’ hosted Web system, that has 8,000 customers and 1,300 projects and programmes currently on the go, with 43,000 users; all in the construction industry. … there are currently 3.7 million documents stored on their system."
I believe the user figure places BO in the middle ground in the UK market, some distance behind BIW Technologies (which claims 67,928 registered users from over 7,000 organisations) and 4Projects who claimed 36,000 users at the end of 2004 but must have grown since.
Incidentally, my efforts within the NCCTP to get a better grasp of the total UK extranet user community (see post) have met with little success.