http://purl.obolibrary.org/obo/pr/pr-dev.obo is the current development version (asserted) of PRO in OBO format. This file may change day to day, and might even be broken. If you use it, understand the caveats. Note that day-to-day development for PRO is done using OBO format, so there is no corresponding OWL PURL. A corresponding GPI file is also available using http://purl.obolibrary.org/obo/pr/pr-dev.gpi.
Other project-related PURLs
http://purl.obolibrary.org/obo/pr points to the PRO Project Home Page
http://purl.obolibrary.org/obo/pr/browse points the PRO ontology browsable using OntoBee
http://purl.obolibrary.org/obo/pr/gpi points to the GPI file for the current release
http://purl.obolibrary.org/obo/pr/tracker points the PRO ontology issue tracker
http://purl.obolibrary.org/obo/pr/wiki points to the PRO wiki (on which this page is kept)
http://purl.obolibrary.org/obo/pr/purls points to this page
PURLs for the project, all of which begin with, are maintained by the OBO Foundry Technical Working Group and by dnatale (Darren Natale) and alanruttenberg (Alan Ruttenberg).