Wiki.js is an open-source, lightweight, and powerful wiki software released under the AGPL-v3 license. Its modern and extensible user interface makes it suitable for all kinds of documents, especially software documents. Wiki.js also provides a WYSIWYG editor for non-technical people and a Markdown editor for developers. This tutorial explains how to install Wiki.js on Ubuntu 20.04 LTS and optionally set up HTTPS using a free Let's Encrypt TLS certificate. * A [Ubuntu 20.04 server](https://www.v......