Akka is an Apache 2.0-licensed toolkit and runtime that simplifies building concurrent and distributed applications on the JVM. Akka supports multiple concurrent programming models, inspired by Erlang. The first version of Akka was released in 2009, it has been actively maintained for 13 years, and the project has 12.4k Stars on GitHub.

Current Fortune 500 companies including Adobe, Apple, Google, Microsoft, Amazon, Disney, General Motors, Starbucks and Tesla are Akka users.

Jonas Bonér, founder and CEO of Lightbend (the company behind the Akka project) and author of Akka, said recently:

We decided to change Akka’s license to ensure a healthy balance between parties, shared responsibility, and in turn contribute to Akka’s future growth.

Jonas Bonér said in a blog post that Lightbend has undertaken most of the support for the Akka project over the years. Since Akka is now considered a critical infrastructure for many large organizations,When a small company undertakes maintenance alone, the Apache 2.0 model presents increasing risks and a huge burden on the company.

The new license that Akka will replace is BSL v1.1 (Business Source License). BSL is a “source code available” license. In the future, developers who want to use Akka in production will need to obtain a commercial license from Lightbend. But Akka’s commercial license will be available for free to companies with less than $25 million in annual revenue, and any new code under the BSL license will revert to the Apache 2.0 license after three years.

We believe that BSL 1.1 with our open source funding and Apache relicensing is a productive and sustainable form of open source. It is easy to understand, provides clear rules, and is enforceable. It provides a mechanism for large enterprises that rely on Akka to give back to Akka, and also allows Lightbend to support their continued success.

Lightbend will start with Akka v2.7, changing Akka’s license from Apache 2.0 to BSL v1.1, with delivery starting in October.