In the Administrator Command prompt window on an GN4 server, switch to the folder where srv4 resides (typically C:\TERA\GN4\bin) and then execute:
srv4 license -show
An example of the possible output:
License Informations
System Guid : 38412bc3-b6c6-41c5-a547-a3038597a160
IP Address : fe80::81f3:afd8:2f0f:21ed%13
Name : TeraDP:Main:GN4
Expire date : 2012-07-27T10:42:06.132Z
Exalead : true
Exalead Advanced : true
Budgets : true
Named users : 100 (1574 configured)
Concurrent users : 30 (0 in use)
Article designer : 30 (1 in use)
Page designer : 30 (1 in use)
Edition designer : 30 (0 in use)
Publish designer : 30 (0 in use)
Tracy designer : 30 (0 in use)
GNXCapture (mobile apps): 30 (0 in use)
InDesign plugin : 30 (0 in use)
InCopy plugin : 30 (0 in use)
Photoshop plugin : 30 (0 in use)
Back4 threads num : 30