Oh how I do love to see more projects go open source! GGPO, a rollback networking SDK for peer-to-peer games that's designed to help hide network latency in fast-paced games that requires precise inputs is now on GitHub.
Created originally by Tony Cannon, one of the founders of the Evolution Championship Series (EVO), GPPO is a well-known middleware in the fighting game scene. It's used in a number of games including Skullgirls, Brawlhalla, Fantasy Strike, Dragon Ball: Zenkai Battle, Killer Instinct and the list goes on. Cannon announced the change in licensing on Twitter earlier today.
Traditional techniques account for network transmission time by adding delay to a players input, resulting in a sluggish, laggy game-feel. Rollback networking uses input prediction and speculative execution to send player inputs to the game immediately, providing the illusion of a zero-latency network. Using rollback, the same timings, reactions visual and audio queues, and muscle memory your players build up playing offline translate directly online. The GGPO networking SDK is designed to make incorporating rollback networking into new and existing games as easy as possible.
Since it's now under the MIT license, any game developer can now make use of it for their games with it being free for commercial and non-commercial use. Hopefully now other contributors can also sort out anything needed for the Linux side of it including documentation, examples and whatever else.
Hat tip to Andrew.