Approach0 is a math-aware search engine. “Math-aware” means you can add math expression(s) as some of your keywords to have search engine help you find similar expressions and return those documents that you may find relevant to your input. In short, a typical search engine plus math search.

Current State

As for now, all basic functionalities are already implemented (see features) and it is ready for using on large data. In fact, it searches over 1 million posts on Math StackExchange in pretty much real time with only two low-end servers hosting 3 search instances.

However, this project is still considered a side project, you may not use it for production for many reasons.