Pieter Wuille has pushed code for a new segwit testnet that features activation via BIP9 as well as support for BIP68, BIP112, and BIP113. In particular, it now supports Lightning Network app development and collaboration.

I encourage everyone to spin up a node and try it out.

For source code, please go to Pieter's github repo:
https://github.com/sipa/bitcoin/tree/segwit4

Feedback is welcome here or on the #segwit-dev channel on Freenode.

- Eric