Working with OWL
The UCI project uses OWL/RDF format documents for the purpose of specifying representation of multi-cloud resources.
The best tool we've found for working with OWL documents is Protege, a free open source application from Stanford University. Downloading Protege requires that you fill in a simple registration form for the project.
http://protege.stanford.edu/
Thanks this is what I needed. I tried 4.0(-beta) first, and it didn't work, so I tried the 3.4. I think they had the same problem: it doesn't like the /xml that is on the first line of the cloud.owl file. I deleted that line, and I was able to load the file. (Maybe I'll use emacs from now on)