. the 2007 equity incentive plan ( the 201c2007 plan 201d ) provides for the grant of non-qualified and incentive stock options , as well as restricted stock units , restricted stock and other stock-based awards . exercise prices in the case of non-qualified and incentive stock options are not less than the fair value of the underlying common stock on the date of grant . equity awards typically vest ratably , generally over four years for rsus and stock options and three years for psus