WARF is the Wisconsin Alumni Research Foundation, an independent, nonprofit foundation chartered to support research at the UW-Madison and the designated technology transfer organization for the university. WARF is a separate entity from the university but partners closely with it. WARF distributes the income from commercial licenses to the UW-Madison, the inventors and their departments. Each year, WARF contributes over $45 million to fund additional UW-Madison research. WARF maintains an investment fund it may use to invest in its start-up companies that meet certain criteria, including the requirement of a suitable co-investor. WARF currently is working with more than 50 active start-ups whose business markets include therapeutics, research tools, biotechnology, medical devices, food and agriculture, engineering, computer, stem cell and clean technologies. WARF currently holds equity in more than 35 of these companies.