Showoff uses many modern web technologies, such as CSS transforms and the Flexbox layout mode that's only been in use for about five years or so.
While we'd dearly love to support your browser of choice, it's genuinely infeasible to do so. Instead, we suggest that you update to a more recent browser. Any major browser released in the last few years will work. Even Internet Explorer 11 or above will work reasonably well.
If you are on a corporate Windows machine with locked down installation privileges, we also suggest trying out Portable Chrome, which will install into a self-contained bundle into your user profile only.