Question:
I assume the web services and web-based GUI of JobScheduler work on top of IIS. Is this true?
Answer:
JobScheduler has two web-based GUIs:
JOC, the JobScheduler Operations Center
A web server is not required to operate JOC because JobScheduler has its own built-in web server.
Read more about Operating and Monitoring GUI - JOCManaged Jobs GUI (depreciated)
At least an Apache or IIS server is required operate the Managed Jobs interface. In addition, the Managed Jobs web interface needs PHP. Read more in the Documentation, see chapter 6.5: JobScheduler: Installation and Configuration
Using IIS as web server is possible. For the configuration of IIS/PHP look at the official IIS and PHP documentation.