According to Wikipedia (link), Beta in software development is defined as below.
Beta is the software development phase following alpha. It generally begins when the software is feature complete. [...] The process of delivering a beta version to the users is called beta release and this is typically the first time that the software is available outside of the organization that developed it.
And, that is exactly what is going on here. We are still working on the site; fixing bugs completing and enabling features.
If something breaks while you're browsing around, please don't be too upset, the system sends us an email when that happens, and we will fix it in a couple hours.