Abba is a library for A/B test analysis. It analyzes tests with binomial outcomes for any number of
groups. You can use the Javascript library (in abba/) to just compute statistics or to render a
nice table summarizing those statistics. There's a handy little app in demo/ which demonstrates
how to use the library. There's a Python version under python/, also available on
PyPI.
You can find plenty more details on the live demo.