Sailfish OS is a general purpose Linux used commonly as mobile operating system combining the Linux kernel for a particular hardware platform use, the open-source Mer core stack of middleware, a proprietary UI contributed by Jolla or an open source UI, and other third-party components. Developed by Jolla
License: Open Source
Sailfish OS is known for its gesture-based navigation and Android app compatibility, making it suitable for users seeking a unique user experience. In contrast, Ubuntu Phone emphasizes convergence and a strong focus on privacy, but suffers from limited device support and a slower development pace.