I started by building an A/B Library for Laravel, since that is my framework of choice, and also has a very large community. The library would handle the A/B testing and local data analytics.
Optionally, the user has the ability to integrate the A/B library with Pivotal Intelligence, which provides API endpoints for the library to share A/B testing analytics and provides more powerful suite of analytics data. From charts, and trends, to carve outs and additional supplemental data.