Another very good one that you probably have never heard of is Compass (German software)
This out of the box links with IV, Acad/M (correctly, not fudged), SE, SW, Pro/E and Catia, so is the only real solution
for mixed CAD environments. It is based on Full Sequel Server (included in the price, full training required for
administration and installation) in a similar way to the Vault and even supports multi-site vaults with replication and
a web client.
http://www.compass-systems.de/start.php?Language=ENGLISH
Big seller in DACH region, and just starting here in the UK.
John Bilton