EHRbase is built on Java and therefore can be run on recent versions of Windows, Linux and MacOS. In any case, it is required to have a postgres database (version 11+) installed and configured.
The easiest way to get started is to obtain and execute a Docker Compose file. More detailed instructions can be found in the EHRbase documentation.
In very short, recent builds can be obtained via docker pull ehrbase/ehrbase:next and the last releases via docker pull ehrbase/ehrbase:latest
The source code can be found on the EHRbase Gitub Project. Instructions how to build the code can be found in the readme file.