Question: I'm trying to get Apache to interpret my Ruby files but I don't understand how to do it. I'm not concerned with Rails right now, only Ruby. What I've found by Googling only confuses me. Any advice?

Answer: 
I've been trying to find the **simple** answer to this question for a while now, and figured out all you have to do is put the ruby script in your webserver's cgi-bin directory and load the corresponding URL. So for example, in my default CentOS 6.2/httpd install, I put a script called hello.rb in /var/www/cgi-bin/ and then loaded up <http://localhost/cgi-bin/hello.rb> in my browser and it executed the script and showed me what went to STDOUT (i.e. from puts, etc).

What happens here is every time the URL is loaded, the script runs completely. This is not ideal for a high volume webserver or where speed is crucial -- so something like fastCGI keeps the script running always, but you have to write the script to handle that. 

hope that helps.
You can execute ruby scripts with fast cgi. Look at the [fcgi project](https://rubyforge.org/projects/fcgi/) for more information.