Open access to high-level data and analysis tools in the CMS experiment at the LHC

The CMS experiment, in recognition of its commitment to datapreservation and open access as well as to education and outreach, hasmade its first public release of high-level data up to half of theproton-proton collision data at 7 TeV from 2010 in CMS Analysis ObjectData format. CMS has prepared, in collaboration with CERN and theother LHC experiments, an open data web portal based on Invenio. Theportal provides access to CMS public data as well as to analysis toolsand documentation for the public. The tools include an event displayand histogram application that run in the browser. In addition avirtual machine is available which contains a CMS software environmentalong with XRootD access to the data. Within the virtual machine thepublic can analyse CMS data; example code is provided. We describe theaccompanying tools and documentation and discuss the first experienceof data use.