Lubuntu is an official Ubuntu flavor based on the Lightweight Qt Desktop Environment (LXQt). The project’s goal is to provide a lightweight yet functional distribution. Along with a simple but usuable graphical user interface, Lubuntu comes with a wide variety of applications chosen for their small footprint so you can browse, email, chat, play, and be productive.

Wiki | https://phab.lubuntu.me/w/
IRC | https://web.libera.chat/#lubuntu
Mailing list | https://lists.ubuntu.com/lubuntu-users
Official website | https://lubuntu.me/