I do not understand how, as Solaris was open previous to Oracle's acquisition.
Red Hat does not maintain all of the code in RHEL - they repackage and patch everything taken from other developers. Very few packages are authored solely by them.
I don't know what relationship Oracle has with the current owner of the UNIX System V source (appears to be The Open Group), but Oracle is responsible for vastly more of the kernel and userspace in Solaris than RHEL.
> Red Hat does not maintain all of the code in RHEL - they repackage and patch everything taken from other developers.
This is false. Red Hat does maintain code that is shipped by default with RHEL. It should be noted though, the number of packages that are part of default RHEL installation is small. Also upstream first policy basically means, any proposed patch must first be merged in upstream before being backported to rhel. If that does not make them maintainers, I don't know what will. Being sole author and maintainer are not the same thing.
Red Hat does not maintain all of the code in RHEL - they repackage and patch everything taken from other developers. Very few packages are authored solely by them.
I don't know what relationship Oracle has with the current owner of the UNIX System V source (appears to be The Open Group), but Oracle is responsible for vastly more of the kernel and userspace in Solaris than RHEL.