Uploading snippets, code, etc

What is the system in which we can contribute to the resource repository?
http://modxcms.com/resources.html

Can I create something like this in ModX?
I was considering a Document Management System or a wiki for our intranet, but I like how there are most downloaded, recently updated, and ratings.

What snippets would I have to use to create something similar?

Hi.. not quite sure what you mean. more than one thought you have?
I think other around here could be very useful.
You could explain again perhaps.