@Plasma is a scalable second-level solution (Layer 2) that allows processing thousands of transactions off the main blockchain while maintaining a high level of security for decentralized networks. Active implementations:

* Polygon Plasma — one of the most successful projects using the Plasma scheme to scale Ethereum

* OMG Network — a specialized platform for payments based on Plasma

* Gluon — Plasma solution for Ethereum from Golem#plasma $XPL