The code is unfortunately written in straight procedural PHP. It is kind of spaghetti code. The end result is quite pretty, but it ignores all of the best practices in PHP development right now.
Also the last time I tried to set it up, it required that I have a twitter account.
There isn't any caching. But, everything other than the index page can be generated fairly quickly, because you're not making database calls, only file system calls.
The index page could take a little longer.
Regardless, it's fairly quick, but it generates the output on each request. Which is to be expected, almost every other tool that isn't manually generated is the same.
