Actually, who knows. Netcraft says Netware, but also says Linux in the web server description.
Netcraft isn't 100% accurate. Probably Open Enterprise Server, which is some sort of Linux/Netware combination, right?
It's possible that it's Open Enterprise Server, which are Novell NetWare services that can run either on top of the Novell NetWare OS or Suse Enterprise Linux 9.
Novell has also been using Apache as their web server since NetWare 6.0, running natively on the NetWare OS.
Mark