I have production server 512 GB RAM and 32 cores, but to be able to users to have access to the server from outside of a local network we decided to use IBM DataPower (its just a gateaway). So let we have 200 concurrent users - what kind of server do I need to use as a web server?
IIS, which is the webserver that comes with Windows Server
QlikView Web Server
Both have pros/cons depending on your infrastructure layout, or what you want/need to implement, and neither is really dependent on the amount of users or RAM/Cores.