WM performance begins to degrade significantly after 10 users are logged in to the server. There is not hard cap on the number of concurrent users per se, however the product will quickly become unusable as more users log in.
To address this it is recommended that a limited set of "power users" be given access to the full WM client. Other users can use the Ultralight client - an HTML only monitoring application that does not consume as much resources as the full Java client.