All Things Ubuntu (ATU) is a library of APIs dedicated to Ubuntu OS for Object Pascal (tested with FreePascal compiler).
The library contains a lot of generic routines that will not be limited to Ubuntu, or not even to only Linux. But the fact is that it is mainly designed for, and tested on Ubuntu, because this is the whole mission of it: make it easier and more popular to write software for Ubuntu with FPC/Lazarus.
Although specifically dedicating the library to Ubuntu seems a narrow choice, however withing this choice there are many flavors and architectures. From Ubuntu on desktop, to Ubuntu Touch (currently ubports.com) and armhf/aarm64 versions on Ubuntu on single board computer like raspberry pi, or other embedded systems. Most of the features should work across all debian based distributions, and a lot should work across Linux generally. Some will also work on arbitrary Unix systems, including OSX, and some even on Windows.
Also, included as a part of the project is the [ATU app], which if installed across Ubuntu-powered devices, will allow all of them to be aware of each other, communicate and act as members of one ecosystem: your desktop, single board computer and mobile device.