Questions about onlyoffice technical aspects

Is rabbitMQ necessary during the installation process? Does onlyoffice have to rely on it to run? What role does it play in the operation of onlyoffice?
In addition to PostgreSQL and MySQL databases, can other databases be used?

Hello @hoshino

RabbitMQ is a dependency so it is indeed necessary for proper work of Document Server. In general, RabbitMQ is used to process requests to the server at faster rate and to prevent high loads on the server. More detailed information about it you can find here:

Document Server supports postgres , mariadb or mysql databases as per available configuration parameter DB_TYPE:

Thank you for your answer. I would like to inquire about which programming languages were used in the development of onlyoffice.

The list of all components of Document Server can be found here:
You can open each component to check used languages in the corresponding section.