Microsoft IIS is not available for Mac but there are plenty of alternatives that runs on macOS with similar functionality. The best Mac alternative is Apache HTTP Server, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 25 alternatives to Microsoft IIS and 16 are available for Mac so hopefully you can find a suitable replacement. Other interesting Mac alternatives to Microsoft IIS are nginx (Free, Open Source), Caddy (Free Personal, Open Source), lighttpd (Free, Open Source) and OpenLiteSpeed (Free, Open Source).
nginx [engine x] is a HTTP and reverse proxy server, as well as a mail proxy server written by Igor Sysoev. It has been running for more than five years on many heavily loaded Russian sites including Rambler (RamblerMedia.com).
Devd is a single statically compiled binary with no external dependencies, and is released for OSX, Linux and Windows. Don't want to install Node or Python in that light-weight Docker instance you're hacking in? Just copy over the devd binary and be done with it.
Tornado is an open source version of the scalable, non-blocking web server. The framework is distinct from most mainstream web server frameworks (and certainly most Python frameworks) because it is non-blocking and reasonably fast.