ACINQ is registered in the French company register as a société par actions simplifiée, created on 25 August 2014 and based at 10 rue de Penthièvre in Paris. The register lists Pierre-Marie Padiou as président and Fabrice Drouin among its officers.
The company and its software are separate things. Eclair is a Scala implementation of the
Lightning Network, released under the Apache 2.0 licence, and its repository dates from
August 2015. ACINQ maintains it. Anyone can run it, and it follows the same BOLT
specifications as Core Lightning and lnd, which is what makes cross-implementation
channels work at all.
The early record is mostly specification work. In September 2016 ACINQ and Bitfury announced a test of the Flare routing algorithm implemented in Eclair across a network of 2,500 servers. A month later, after Scaling Bitcoin in Milan, ACINQ and others published an outline agreement on the scope of the Lightning protocol. In March 2017 the company released Eclair 0.2-alpha1, which it describes as the first BOLT-compliant Lightning implementation. In December 2017 it announced version 1.0 RC of the specification together with a successful cross-implementation test on mainnet. That sequence, agreeing a document and then proving two independent codebases could pay each other, is the reason Lightning is a network rather than a product.
The company raised 8M in October 2019 led by Idinvest Partners, bringing total funding to $10M by its own account.
Today ACINQ ships Phoenix, a self-custodial wallet with native Lightning support rather than a hosted account, and phoenixd, a stripped-down node meant only to send and receive. It also operates a routing node that it describes as the best connected on the Lightning Network, which makes the company both an author of the protocol and an interested party in how the protocol develops.