EasyOS was created in 2017, derived from Quirky Linux, which in turn was derived from Puppy Linux in 2013. Easy is built in woofQ, which takes as input binary packages from any distribution, and uses them on top of the unique EasyOS infrastructure.
Throughout 2020, the official release for x86_64 PCs was the Buster-series, built with Debian 10.x Buster DEBs.
EasyOS has also been built with packages compiled from source, using a fork of OpenEmbedded (OE). Currently, the Kirkstone release of OE has been used, to compile binary packages for x86_64.
Earlier releases of EasyOS compiled in OE are the Dunfell-series and before that the Pyro-series. They have also been compiled for aarch64 and EasyOS runs on the Raspberry Pi4.

Visit the EasyOS website here:

https://easyos.org/