Since 2003, the research centers belonging to the Helmholtz Association (HGF) have been financed according to a concept called program-oriented funding. Financing is oriented towards long-term research programs in which several research centers participate. The Senate of the Helmholtz Association evaluates the research programs with the aid of external reviewers in a competitive process. Its recommendations provide the basis for the funding of the program parts of the participating centers. The German Federal Government provides 90 percent of funds, the State of Baden-Wuerttemberg provides the remaining 10 percent. Further financial sources are external funding, license revenues, and donations.