When you have a web server application which is written also in c++, running c++ on a web is very straight forward and technically easy.
First have your web server application keeps listening to port for instance 80 and when there is HTTP request just parse the request header and get the requested page.
Secondly, if the page is purely static HTML all you need to do is to open and read the file then send back to the client browser. If the page is C++, your web server application will do the following process.
1) Parse the page file and extract the codes then create CPP file
2) Compile the CPP file and when there is no error just generate DLL (for WINDOWS) or SO (for UNIX), otherwise create an error file just open and read then send to the client browser
3) Load the DLL or SO into the memory from the server side.
These 3 simple process are required to run C++ on a web and this requires strong motivation, dedication and patient because you will encounter a lot of problems here such as memory leak.
If the video cannot be played, please click here [YouTube: Managing to run C++ on a web].