Infiniband is very much an industry standard:

https://www.infinibandta.org/member-listing/

As far as I know, everyone is free to sign up with the infiniband trade association and implement the specification.

Furthermore, if you use RDMA over Ethernet, you are using infiniband at a low level. RoCE which enables it was originally called Ethernet over infiniband. It is maintained by the infiniband trade association.

Omnipath was Intel’s failed effort to try to kill an open standard. It purchased QLogic’s infiniband business, killed it in favor of omnipath and sold it when it failed.