Amazon recently announced the release of OpenSearch, a fork derived from versions 7.10.2 of ElasticSearch and Kibana. OpenSearch is licensed under the Apache License, V2 (ALv2). Elastic recently made adjustments to their Elastic License to simplify the usage of their code for non-commercial purposes.
The product team behind this release calls the OpenSearch project a "a community-driven, open source fork of Elasticsearch and Kibana". They continue to explain that:
Our goal with the OpenSearch project is to make it easy for as many people and organizations as possible to use OpenSearch in their business, their products, and their projects.
The OpenSearch project will be the new home for the previously released Open Distro for Elasticsearch. The features released under Open Distro, including security, altering, machine learning, SQL, and index state management will be added to OpenSearch. The Amazon Elasticsearch Service will be renamed to the Amazon OpenSearch Service.
The OpenSearch service will offer a choice of open source engines including the ALv2 licensed Elasticsearch versions (7.10 and earlier) and all new versions of OpenSearch. Amazon has committed to supporting and maintaining the ALv2 versions of Elasticsearch and Kibana with security and bug fixes, however all new feature work will be done against OpenSearch and OpenSearch Dashboard (the rebrand for their Kibana fork).
To facilitate contribution, all code within the OpenSearch repo is licensed under the ALv2 license. Additionally, they do not ask for any form of contributor license agreement (CLA). While Amazon will remain the primary steward and maintainer of the repo, they have created guiding principles for those looking to contribute.
In preparing OpenSearch Charlotte Henkle, senior software development manager at Amazon OpenSearch, notes the team took the full git history, minus branches and tags, of the 7.10 branch. This was done to retain proper attribution to the original authors. All code that was not compatible with the ALv2 license was then removed. This included all Elastic X-Pack code as well as disabling all telemetry collection functionality.
This release is not without controversy. In 2019, Amazon released their Open Distro for Elasticsearch. At the time Jeff Barr, chief evangelist for AWS, explained that "this is not a fork; we will continue to send our contributions and patches upstream to advance these projects." Some viewed this as a response to Elastic partially open-sourcing their previously proprietary X-Pack code under their new Elastic License. This led to Elasticsearch no longer being a fully APv2 licensed project.
More recently, Elastic moved away from the APv2 license entirely by adopting the Server Side Public License (SSPL) and the Elastic License. Currently the Open Source Initiative does not recognize SSPL as an open source license. However as Shay Banon, founder and CEO at Elastic, notes: "Our license change is aimed at preventing companies from taking our Elasticsearch and Kibana products and providing them directly as a service without collaborating with us."
After this announcement, Elastic released an update to their Elastic License. As Banon describes,
The Elastic License v2 (ELv2) is a very simple, non-copyleft license, allowing for the right to "use, copy, distribute, make available, and prepare derivative works of the software" and has only three high-level limitations.
One of those limitations is that the license does not permit providing the product to others as a managed service. The new ELv2 license applies to all of Elasticsearch and Kibana, both the distributions and the source code for all free and paid features. The SSPL license continues to remain an option for the source code as well.
The community reaction to both announcements is mixed. Colin Percival, developer at Tarsnap, noted on Twitter that he disagrees with Amazon calling OpenSearch a fork:
Elasticsearch is a fork of Elasticsearch, because they're the ones who changed the license. Amazon is just continuing the original open source project which Elasticsearch abandoned.
Reddit user -proton was not so positive about Amazon's intentions noting:
Amazon isn't doing this for the community. They're doing it for themselves - they’ve made billions already from Amazon elasticsearch service and don't want the money to stop with the new license.
The OpenSearch team indicates that this initial code should be considered to be in an alpha state and is not production-ready. They anticipate moving into a beta release in the upcoming weeks with the code base being production-ready by early summer.