Okay two posts with funny acronyms in a row, sorry! The previous one was playing around but this one is real, Wide Area File Services (WAFS).
I spoke with Marc at Globalscape yesterday. They have been providing services for file replication/mirroring (among other things) for many years but recently they've been focusing on solving the Revit central file collaboration situation. More and more firms are trying to share work among their own offices as well as among other consulting firms. The first is a little easier to solve when the firm is dealing with its own wide area network ("intranet" WAN). The second is harder, harder still when firms are not able to share a common network resource regardless.
What is intriguing about them is that it is a software solution applied to project servers. One firm takes the lead as primary and purchases software ("agents") equal to the number of team member firms involved. The primary firm's project hub server gets its own server side software agent. The lead firm distributes agents to each firm that is part of the team. This hub server and the other agents manage Jobs (shared projects and their folders) and use a Vault (file access data) that keeps the single central file replicated at each agent site.
From their "BIM meets WAN" site page:
Facilitating multi-user, multi-site collaboration is often one of the most challenging obstacles for organizations. When you pair Autodesk® Revit® Worksharing capabilities with GlobalSCAPE WAFS users from locations across the world can access and share files over a WAN at LAN speeds. This means faster and more reliable element borrowing and multi-user access to entire worksets.
More specifically, file replication ensures current copies of the central files and worksets exist at all locations that require collaboration. Real-time file locking prevents users from concurrently borrowing the same workset or entity. Once a user is finished, the common Save-to-Central command publishes changes back to the local central file copy, and then WAFS instantly mirrors those changes and unlocks the workset at all sites on the network.
From the Revit user perspective they really have no idea what is going on behind the scenes. They create local files, work and synchronize with central as usual. The software does the work behind the scenes. They can use Revit's companion application Worksharing Monitor to see what other users are up to which is invaluable when teams are spread far and wide.
Interested in learning more? Visit their website. They have a couple documents you can review (though I couldn't find convenient links on the site for them) and a video you can watch.