Simple CGI programming
A simple HTTP server serves static HTML, Javascript, CSS, Images, etc. Sometimes you need a bit of dynamic content from the server-side. There are simple microframeworks to mega frameworks to achieve this. You could use any of these available web frameworks on the server side. But let’s say you don’t have access to any of those frameworks, and you want it to be simple and lightweight. You could try CGI.
Or you are just a web geek and want to spend an hour on old but interesting technology.