One of the OpenXR runtimes that has risen in popularity these past few years is called Monado. Monado is developed as an open-source project and is licensed under various permissive licenses explicitly listed here: https://gitlab.freedesktop.org/monado/monado/-/tree/main/LICENSES. The main goal of the project is to improve the general suitableness of Monado when used for XR display devices and companion devices as well as enhance various select key features that are considered important by Khronos.
This RFP is being circulated to the public. - any interested organization or individual is welcome to respond. Proposals, and any questions directly related to preparing a proposal, should be sent to the Khronos mailing list at openxr_monado_improvements_rfp@lists.khronos.org. Companies considering making a bid in response to the RFP should notify the RFP list as soon as possible. The deadline for receipt of proposals is 6:00 AM PT on Thursday, 3 August 2023.