XtratuM was released as free and open-source software, subject to the requirements of the GNU General Public License (GPL), version 2 or any later.

[1] XtratuM is a hypervisor designed for embedded systems to meet safety critical real-time requirements.

It provides a framework to run several operating systems (or real-time executives) in a robust partitioned environment.

XtratuM would be the first layer of software (the one closest to the hardware), which provides a solid basis for the rest of the system.

XtratuM 1.0 was initially designed as a substitution of the RTLinux HAL (Hardware Abstraction Layer) to meet temporal and spatial partitioning requirements.