Capability-based Reliable Operating System (CapROS) is an operating system incorporating pure capability-based security. It features automatic persistence of data and processes, even across system reboots. Capability systems naturally support the principle of least authority, which improves security and fault tolerance. It is free and open-source software released under the GNU General Public License version 2 (GPLv2), and GNU Lesser General Public License version 2 (LGPLv2).