Thus, there's no absolute rule that serving a static state must faithfully map to filesystem representation except convenience. Nor, do dynamic requests need to map to include the details of dynamic handler URIs unless the application cannot change generated links.

Revealing backend state, while somewhat Security Through Obscurity (STO)(TM), it's unwise to volunteer extraneous information without a purpose. Preferably, some other simple, one-way hash external representation should be used.

I played client-side Netscape JS and Apache HTTPd CGI bash shell scripts (not even Perl) to write a toy multiuser chat app in 1996. IIRC, it used a primitive form of long polling where it kept an HTTP/0.9 session open with keepalive commands periodically and then broadcasted the message received to all other users who were also connected.

3.3M LoC C++, that must have been quite painful.

I also used to ask myself why they would expose the filename of the DLL.