Trying to learn about about online event registration software.

I work with a charity fundraiser event, and we are hoping to create a new website with a good online registration feature.

Here is a link to a similar organization, specifically to their registration page. This is not our organization, (but it is a darn good cause if you're interested).

Patrick Williamson Foundation

Can anyone tell me what type of e-commerce system is used on this site? We have a company that hosts and manages our website, but I'm trying to research a few options to suggest to them.