Complex sentence: Endless OS is built on top of the Linux kernel and many other open source technologies though unlike most Linux distributions it uses a read-only filesystem managed by OSTree for OS updates and Flatpaks for application delivery and update.
Split into simpler sentences: Endless OS is built on top of the Linux kernel and many other open source technologies. Unlike most Linux distributions, it uses a read-only filesystem managed by OSTree for OS updates and Flatpaks for application delivery and update.