Deepening our Open Source commitment

We are very proud to announce that we are open-sourcing most of the functionality previously available in AxonDB and AxonHub into a unified platform - Axon Server. Axon Server will be accompanied by two new commercial offerings - Axon Server Enterprise and Axon GDPR Data Protection Module. We are also realigning the Axon Framework towards Axon Server and offering a new simplified, combined platform named Axon 4.0. You can download the latest version from our website. These changes represent a major step towards further deepening our long-term commitment to open source and are worth explaining briefly. In the coming weeks and months, we will be sharing far more details on these offerings.

The Details

As you are likely aware, we launched AxonDB and AxonHub earlier this year to complement the popular Axon Framework (on a celebratory note, the Axon Framework recently crossed one million downloads!). While the Axon Framework has always been open-source, the same was not the case for AxonDB and AxonHub until now. The driving force behind AxonDB is to provide a high-performance, purpose-built event store. Similarly, the driving force behind AxonHub is to make scalable distribution and routing of commands, queries, and events across nodes as easy and robust as possible.

The, now open-source, Axon Server supports all of this functionality to the extent that is appropriate for basic deployments of Axon. This is certainly true of evaluation, development, testing, and small deployments of Axon applications. Specifically, Axon Server supports purpose-built event storage, routing, manual scaling of tracking processors, event store queries, basic monitoring, basic security, and basic messaging interoperability.

Axon Server Enterprise is targeted towards mission-critical, medium to large-scale production deployments of Axon Server. Features include clustering, advanced monitoring, advanced metrics, advanced security, higher performance storage, higher performance routing, automatic scaling, multi-context support, and advanced messaging interoperability.

While the Axon Server editions cover most deployment scenarios, the feature pack covers specific, narrower use cases. Like Axon Server Enterprise, the feature pack is not open source. Axon GDPR Data Protection Module is targeted towards high sensitivity enterprise environments and includes features like privacy guards, data migration tools, data encryption, and automated backups.

As is the case today, all of these offerings (Axon Server, Axon Server Enterprise, and the Axon GDPR Data Protection Module), as well as the Axon Framework, are covered by a suite of support, training, and consulting options.

A significant change is that we have realigned the Axon Framework 4.0 defaults to use Axon Server out of the box, both for event storage and message routing. Of course, it is still possible to use things like AMQP to distribute events or JGroups to distribute commands. Still, Axon Server will provide a much easier and more maintainable solution to scaling your applications. The ease-of-use goal is perhaps most evident in our new Axon 4.0 offering that bundles Axon Framework and Axon Server together in a single download that will help you get started with Axon in the most productive way possible. Other than the realignment, Axon Framework 4.0 includes a small number of important API improvements.

Why the Convergence?

Since AxonDB, AxonHub, and the GDPR Module release, a couple of things have become clear. Also, these components are intrinsically linked, including the Axon Framework. Keeping these separated makes communication, documentation, maintenance, support, and usability more difficult than they should be. More importantly, these factors caused confusion as to when to use these components separately and when to use them together. Converging the Axon platform around Axon Server makes it significantly easier for us to communicate the easiest, most robust way of using our offerings end-to-end. The Axon 4.0 offering takes the convergence a step further.

Why Open Source?

If the software is eating the world, open-source is eating software. There are excellent reasons for this that probably do not need to be elaborated too much here. Open-source software makes collaboration, transparency, adoption, and fostering a community easier. It helps you avoid vendor lock-in and makes debugging as well as contribution easier. These factors are especially crucial for globally important parts of technology infrastructure like Axon.

AxonIQ’s goal is to improve the way we build our systems drastically. To achieve this goal, the tools and methodologies needed to achieve such a change must be easily accessible. For example, customers who started with AxonDB and AxonHub from their projects have reported a significant reduction in complexity and time-to-market. However, having these products as closed source only has proven to make it difficult for users to include them in their evaluation cycles. By making Axon Server open source, we provide a very easy-to-use alternative, accessible for everyone. This is, of course, in addition to the more conventional reasons often cited for open-source such as increased collaboration and contribution.

Why the Commercialization?

The paradox of open-source - like most great ideologies - is embracing it from a purist’s standpoint often leads to bad outcomes. The evolution of Axon Framework and AxonIQ is a great case in point. For many years the Axon Framework was the work of one man’s passion, a small community, and open source in its purest sense. AxonIQ is a far more recent phenomenon. However, the reality is that the evolution of Axon has accelerated significantly during this short time span already in terms of features, maturity, stability, quality, documentation, evangelism, support, and, yes, also adoption. The end result is that everyone has benefited - probably most of all existing Axon Framework users.

The key to the success of AxonIQ and the sustainable evolution of Axon is practical and reasonable commercialization. For enlightened customers who depend on Axon for significant parts of their success, it is obvious that AxonIQ, rather than simply Axon, remains solidly successful in the long term. If Axon helps your company make money, paying a small fraction of that money back to Axon helps make sure your investment in the technology remains secure, and you get the most out of it. This is especially true if you need the full extent of the features we offer, including our support, training, and consulting.

The most honest way we have found to keep modest, sustainable commercialization a reality and minimize undue conflicts of interest (such as poor documentation that forces users to buy support) is through selling licenses of our commercial, non-open source offerings. This is, of course, in addition to the support, training, and consulting options that are there for customers for whom it is most appropriate. This is a delicate balance to which there will never be universal answers, but we are confident this is the right balance for Axon in the foreseeable future.


We have taken the courageous step of streamlining and open-sourcing AxonDB and AxonHub into Axon Server and Axon 4.0. In addition, we are introducing Axon Server Enterprise Edition. Axon Framework continues to develop, as will do our support, training, and consulting offerings further, and yes, the team of AxonIQ is growing rapidly with it on a global scale. We believe these changes will lead to greater ease of use and adoption of Axon. It is also the right thing to do to maintain a long-term sustainable business at AxonIQ that benefits everyone.

As always, we are thankful to our customers and community. We look forward to hearing from you!

Allard Buijze
Founder and Chief Technology Officer. Allard is a global thought-leader on event sourcing. He is a recognised expert with more than 20 years experience, including microservices, event sourcing and event-driven architecture. Allard advocates for better collaboration between developers and business.
Allard Buijze