Open Ravenscar Real-Time Kernel

Funded by ESA/ESTEC, EC FP7, and the Spanish R&D&i plan

The Open Ravenscar Real-Time Kernel (ORK+) is an open-source real-time kernel of reduced size and complexity, which can be used to develop high-integrity real-time applications in a subset of the Ada 2005 language compatible with the Ravenscar Profile, an Ada tasking profile for high-integrity systems.

ORK was originally developed under ESA contract, based on Ada 95 and targeted to ERC32 computers. The current version, ORK+, is written in Ada 2005 and runs on bare LEON computer boards and on XtratuM for LEON.


ORK+ is integrated with the GNAT GPL compilation system, developed by AdaCore. The kernel and a modified runtime library are packaged together with the compiler and other tools into a comprehensive package, GNATforLEON. compilation chain tools are hosted on GNU Linux workstations.

GNAT/ORK+ for XtratuM

A version of GNAT/ORK+ running on top of the XtratuM hypervisor for LEON3 computer platforms has been developed. GNATforXtratum compilation chain tools are hosted on PC/GNU Linux workstations.


ORK+ is written in Ada. It is free software, and is distributed under a GPL license, which allows you to freely run, copy, distribute, study, change and improve the software. The GPL does not allow you, in turn, to remove these freedoms from other users.

If you are interested in a professional license please contact us.