[Kyng]

The theme they used was based on Apart Night from way back in the day. It was the most popular theme on the 1.6.x release, but that was made before people truly got a feel for the capability of MyBB.

At the time, people were amazed that you could take a forum that looked like it was made in the 90s and turn it into something that looked like IPB. Today, people use myBB for that purpose all the time (it's the perfect software to theme the living daylights out of), but as always, it remains years behind out of the box.

People don't ever really use MyBB for its default theme, so I'm okay with it ultimately. However, not being responsive (as @Kyng mentioned) means that most user themes aren't responsive either. We made our theme from scratch and had to do responsiveness manually on an entirely table-based design. It's nowhere near complete. It's enough to get by, but doing it entirely from scratch is a nightmare.

Yeah, I can imagine >_< . When I first started using MyBB, I planned to create my own set of responsive templates; however, I soon realised just how much work that would be, and scrapped the project. 

I just ended up using BootBB as a base for my responsive themes, since that's available for free under a relatively permissive CC BY-SA 3.0 licence. Not perfect by any means, but again, it's enough to get by.