While AUX is available under an open source license (GPL 3, see COPYING file), DeusO GmbH uses AUX commercially, including offering the library under proprietary licenses.
This prevents us from accepting external contributions to the library, unless the contributor agrees to either assign the copyright for their contribution to DeusO GmbH, or grants DeusO GmbH a license allowing DeusO GmbH to treat the contributions entirely as if DeusO GmbH held the copyright to them. This means that your contributions also must be unencumbered by rights of any other person or entity, meaning that for example they may not include code from other projects even if they are released under an Open Source license.
When submitting contributions, please kindly indicate that you agree to these conditions, for example by stating
I offer this contribution in accordance with the terms laid out in the CONTRIBUTING.md document from the AUX repository.
By offering my contribution, I confirm that the contribution is free from any third party rights, and I assign the copyright to DeusO GmbH or, if that is not possible, grant DeusO GmbH a world-wide, exclusive, non-revokeable license to treat my contribution entirely as if DeusO GmbH owned the copyright to it.