Sometimes the most exciting research ideas don't meet the criteria for government funding, or they exist outside the limits of current budget restrictions. The Dean's Innovation Fund supports these sorts of initiatives and does so with an agility not often possible with other forms of sponsored research.
This fund also allows the dean to support efforts that improve the quality of life for SCS graduate and undergraduate students. For example, once upon a time a faculty member had a cool idea that received funding from the Dean's Innovation Fund. That cool idea turned into DuoLingo.