This excerpt taken from the HPQ 8-K filed Nov 12, 2008.
Stock Purchase Plan
Under the Stock Purchase Plan, eligible employees may purchase EDS common stock at the end of each fiscal quarter at a purchase price equal to 85% of the lower of the market price on the first or last trading day of the quarter, through payroll deductions of up to 10% of their compensation, not to exceed $25,000 per year in market value. Shares of EDS common stock purchased under the plan may not be sold or transferred within one year of the date of purchase. The number of shares originally authorized for issuance under this plan is 57.5 million. Total compensation expense recognized under this plan was $6 million during each of the years ended December 31, 2007, 2006 and 2005.