On this site

Development information
Build Reproducibility
Supported Hardware
Formal Verification
User support and documentation
Code of Conduct
About this site

External links

Savannah site
Git development repository
Mailing lists

Ironclad is a formally verified, hard real-time capable kernel for general-purpose and embedded uses, written in SPARK and Ada. It is comprised of 100% free software, free in the sense that it respects the user's freedom.

Some of the supported features are:


Further news can be read here.


Ironclad uses semantic versioning. Support and bug fixes will be done for major versions for no shorter than 6 months since release, to be extended as seen fit.

Version Released End of life Downloads Documentation
0.5.0 2023-Oct-31 Not stable [.tar.gz] [.sig] [html] [pdf]
0.4.0 2023-Aug-31 Not stable [.tar.gz] [.sig]
0.3.0 2023-Apr-02 Not stable [.tar.gz] [.sig]

All releases are signed using PGP, please check the signatures before using the downloaded tarballs using the release keyring.

Who uses Ironclad?

Some distributions use Ironclad as its kernel, for example, visit Gloire, a general purpose desktop OS using Ironclad along GNU userland tools.

Thanks to

GNU Savannah Limine Free Software Foundation AdaCore Managarm