[bpicolo]

There's a bunch of feature toggles libraries out there for pretty much every web language you can think of. Doing it statically is pretty easy, you can rewrite a similar library in a day or two. One Ruby[0] and Python[1] example below, but there are tons.

What you don't get out of those libraries alone is a couple things. One is a metrics pipeline if you want to actually A/B test and gather metrics on the success of different features. That's a hard problem because A/B metrics collection pipelines are something pretty much something everybody reinvents from scratch right now to fit their combination of language/logging tool/cloud host/data warehouse/BI tools/whatever.

The other big one is the managed configuration deployment - a UI that you can toggle features on and translate those to appropriately flipped toggles in all of your clients (mobile, web backend, web frontend, whatever). That's a pretty big task to do and requires a hosted service one way or another. Flipper (below) looks like it integrates into a rails service and so has a UI, which is kinda neat (first time I've noticed an OSS solution that does that part - looks like theres a number of options that do this now), but you'd still need to reinvent tooling for mobile apps and such with it.

[0]: https://github.com/jnunemaker/flipper [1]: https://github.com/disqus/gutter