Dendron was an experimental Matrix homeserver written in Go.
Rather than write a Matrix homeserver from scratch, Dendron acted as a proxy for an existing homeserver Synapse written in python. This meant that it could be used as a fully-featured homeserver.
The Dendron experiment mainly served to give us an excuse to learn Go and reveal that a strangler-pattern style rewrite like this isn't a clear win. The additional hop of the dendron loadbalancer/proxy caused operational complexity (additional timeouts; logging; IP rewrites; FD limits; etc) whilst buying nothing that a normal LB couldn't do. Also, the strangler-pattern didn't give us enough freedom to rapidly fix the problems of Synapse's DB schema and storage layer.
As of March 9th 2017, matrix.org's Synapse is no longer running behind Dendron (but instead using a normal haproxy), and meanwhile all our next-generation homeserver development effort is going into Dendrite (aka "Dendron done right" ;D), which in turn is built on gomatrixserverlib, matrix.org/util, and other libs.
Currently to use Dendron you will need an development install of Synapse. See these instructions for setting up a dev install of Synapse.
To build Dendron itself check out this repository and build it using gb:
gb generate
gb build
WARNING: Dendron is currently in the early stages of development. These instructions are likely to change frequently and no effort is made to provide backwards compatibility.
You will need to configure Synapse to use PostgreSQL for storage.
You will need to setup an unsecure HTTP listener for Dendron to proxy requests to.
The configuration for Dendron is passed on the command line.
Dendron can be tested using SyTest, a black box matrix integration tester. See the SyTest project page for instructions