Please, try and be more specific in your questions. There are three major versions of Qlikview that are currently released and supported - which one are you using?
If you are using v10, make sure to install the Qlikview SDK, as a part of the Qlikview Server installation, where you can find full documentation for the QMS API; the Qlikview Server/Publisher API in v10.
Thank you. That was very helpful. I installed the SDK and looked at the samples and help DOCs. It still doesn't look like I will be able to get the licensing details from the QVS API. Can you confirm?
My goal is to write a Windows Application in C# that will be used by selected high profile employees in our company to view QlikView license usage. The application should be able to tell the user who has doc CALs, user CALs etc. and their usage thereof.
You don't need any specific licensing to use the QMS API. You do however need to get the newest version of the web service reference from the QMS to be able to communicate with the API's. To do this; please right-click on the Web References node in the project explorer, select the QMSBackend service (or what it is named in your solution) and select Update (or such).
When that is done, can you run the example? What is the error message? How far do you come?
Regarding your second question; you can get all CAL data from QVS via the QMS API, yes. However, it is not possible to see user activity history via this interface - for that, you need to review the QVS session log, which logs all client CAL usage and such. I believe that a "mash-up" between these two might be the only way.