So what are in a nutshell the options for webserver programming?

Too many to enumerate - but I'll try and summarise.  Briefly, there
are several decisions you have to make, including:
  * Power.  Is it up to a complex task?
  * Complexity.  How much programming manpower is it worth?
  * Portability.  Might you want to run your program on another system?
So here's an overview of the main options.  It's inevitably subjective,
but may be helpful to someone:
Basic SSI:  Simple interface for basic dynamic content.
   Non-standard - read your server docs.
Enhanced SSI[1]: Suitable for more complex tasks within
   an HTML page.
CGI:   The standardised, portable general-purpose API,
   not limited to working with HTML pages.
Enhanced CGI-like[2]: Typically gain efficiency but lose portability
   compared to standard CGI.
Servlets:  An alternative API for JAVA, that overcomes
   the limitation of JAVA not supporting
   environment variables.
Server API:  Generally the most powerful and most complex option.
[1] For example, PHP, ASP.
[2] For example, CGI adapted to mod_perl or fastcgi.