BPMN is the most under appreciated technology in our field IMO.

Agreed. And the ideal language to build a backend interpreter for bpmn - I am doing so - is elixir imho (a language to build build massively scalable soft real-time systems with requirements on high availability, see f.e ds.cs.ut.ee/courses/course-files/To303nis%20Pool%20.pdf ).

From the Zeebe README: "Zeebe is currently a tech preview and not meant for production use".

I'm on the team that's building Zeebe and want to mention that we release new "dev preview" versions on average once per month and are aiming to have a production ready 1.0 by the end of 2018. If anyone has questions or ideas, or wants to build a prototype with Zeebe, it'd be great to hear from you. There are various ways to contact us here: https://zeebe.io/community/

I think "any" is signalling: "hey we want to support any language, contribution welcome", that is better than wondering on the project and thinking "oh it's for go, nevermind, I need it for python" :)

AFAICS this still requires a Java broker. Only the client is in go.

Zeebe is indeed a Java application, but it's possible to use Zeebe without writing any Java. Broker operations can be managed with a CLI (https://github.com/zeebe-io/zbctl). Along with the Go client, there are experimental Node, Ruby, and C# clients, but these are community contributions that aren't yet officially supported by the project.

Hello smarx007. Sorry for the late reply. Gaia is not BPMN. You can actually compare it with Jenkins Pipelines but with the advantage that you can basically use any programming language. And no, "any" programming language does not mean Go. Gaia is alpha, that is the reason why we currently only support Go. We will support other languages soon. :-)