TL;DR: I know the bitcoin community can be toxic, so it’s even more remarkable how joyously friendly everyone in the (much smaller!) lightning development community is as we refine the spec. If you’ve wanted to work on this kind of thing, and like thoughtful people, please dive in! Read the spec and hack on an implementation!
There are really 4 teams working on their implementations of the spec, and refining it as we go. Original paper co-author Joseph Poon co-founded Lightning Labs (note: hiring!) with the amazing Laolu. Laolu is doing the heavy lifting on the spec: He wrote the inter-peer crypto spec (using noise), but hacks on everything else too. His enthusiasm is contagious. Code here.
Tadge is the other paper co-author, now at MIT’s DCI, and his explanations to me on outsourcing watching were amazing: insightful, canonical and considered. He’s also working on an implementation, and his sense of humor is almost worth learning Go for…
Pierre-Marie Padiou and Fabrice Drouin at ACINQ are implementing in Scala, and both are amazing to work with. Pierre and I are currently debating which of two competing changes (“his” or “mine”) we should apply to the spec; the level of respect and consideration in this debate is what triggered me to blog about how much delight I get working with everyone involved. Plus, they’re French which lends a level of cool to the rest of us by association. Right? Right?
Finally, there’s Christian Decker and me, implementing in C. We’re mainly trying to produce a reference implementation, though we’re rewriting as a suite of daemons to meet the current spec. We’re also delightful to work with, of course!
We have an IRC channel (#lightning-dev, plus per-project ones like #lnd), a mailing list (http://lists.linuxfoundation.org/pipermail/lightning-dev) and an very active github for the spec. If you want to join an existing implementation, or implement your own, please reach out to any of us and join our community!