This excerpt taken from the NDAQ 8-K filed Feb 20, 2008.
Research and development costs
Development expenses are capitalized under IFRS when an entity can demonstrate the technological feasibility to complete the development of the product together with other specific criteria. Capitalization ceases and depreciation begins when the product becomes available to customers. Under U.S. GAAP, software development expenses are capitalized after the product has reached technological feasibility. As a result of this, certain software related development costs capitalized under IFRS are not capitalizable under U.S. GAAP and therefore are expensed as incurred, net of any amortization added back.
Details of U.S. GAAP adjustment: Capitalized development costs