Written in C. Wrapped in Ruby. Faster than proving Fermat's Last Theorem.
The library uses a Bison grammar that emphasizes an adherence to AMS-LaTeX math. The grammar is safe and discards any syntax it doesn't understand.
Reflowing a page is silly; serve your documents whole. And although this particular library is wrapped in Ruby, 90% of the transformation is performed in C. Go forth and write more wrappers!
Don't like SVGs? That's fine! Mathemtical can return a PNG or plain MathML, too.