If you're afraid of running out of memory by using Redis, or want your forum to be more easily scalable, you can install NodeBB with MongoDB. This tutorial assumes you know how to SSH into your server and have root access.
**These instructions are for Ubuntu. Adjust them accordingly for your distro.**
The latest and greatest MongoDB is required (or at least greater than the package manager). The instructions to install it can be found on the `MongoDB manual <http://docs.mongodb.org/manual/administration/install-on-linux/>`_).
Like MongoDB, the latest and greatest node.js is required (or at least greater than the package manager), so I'm leaving this to the official wiki. The instructions to install can be found on `Joyent <https://github.com/joyent/node/wiki/Installing-Node.js-via-package-manager>`_.
NodeBB can also be started with helper programs, such as [``supervisor`` and ``forever``](https://github.com/designcreateplay/NodeBB/wiki/How-to-run-NodeBB). You can also use `nginx` as a [reverse proxy](https://github.com/designcreateplay/NodeBB/wiki/Configuring-nginx-as-a-proxy-to-NodeBB).