2010 10-K: Part II 9. Property, Equipment, and Capitalized Software 10. Operating Leases 11. Stock-Based Compensation Stock-Based Compensation Plans In November 2004, we adopted the 2004 Stock Incentive Plan. The  2004 Stock Incentive Plan provides for grants of options, stock  appreciation rights, restricted stock units, restricted stock, and  performance shares. All of our employees and our non-employee  directors are eligible for awards under the 2004 Stock Incentive  The following table summarizes our rent expense including taxes,  insurance, and other operating costs: The following table shows our minimum future rental commitments  due in each of the next five years and thereafter for all non-cancel- able operating leases, consisting primarily of leases for office space: We include our liability for vacant office space, as appropriate, in  “Accounts payable and accrued liabilities” and “Other long-term  liabilities” on our Consolidated Balance Sheets. The following table  shows the change in our liability for vacant office space from  December 31, 2008 to December 31, 2010: In 2010 and 2009, we recorded changes to our liability for vacant  office space, primarily for the former Ibbotson headquarters. We  increased the liability related to this vacant office space because  we anticipated receiving lower sublease income and expected it  would take more time than previously estimated to identify a tenant.  In addition, we increased our liability for vacant office space related  to the equity research and data business acquired from CPMS. Liability for Vacant Office Space Deferred rent includes build-out and rent abatement allowances  received, which are amortized over the remaining portion of the  original term of the lease as a reduction in office lease expense.  We include deferred rent, as appropriate, in “Accounts payable and  accrued liabilities” and “Other long-term liabilities” on our  Consolidated Balance Sheets. The following table shows our property, equipment, and capitalized  software summarized by major category: The following table summarizes our depreciation expense: As of December 31 ($000)  2010 2009 Deferred rent  $ 28,293 $ 25,613 As of December 31 ($000)  2010 2009 Computer equipment  $ 36,274 $ 29,907 Capitalized software  27,308 25,659 Furniture and fixtures  18,816 17,057 Leasehold improvements  44,131 39,216 Telephone equipment  2,599 2,199 Construction in progress  1,545 560 Property, equipment, and capitalized software, at cost  130,673  114,598 Less accumulated depreciation (68,568)  (54,770) Property, equipment, and capitalized software, net  $ 62,105 $ 59,828 ($000)  2010 2009  2008 Depreciation expense  $14,814 $ 12,998  $ 9,348 Liability for vacant office space ($000) Balance as of December 31, 2008  $  761 Increase liability for vacant office space 3,172 Reduction of liability for lease payments (978) Increase liability for vacant office space related to acquisitions  376 Other, net  40 Balance as of December 31, 2009  3,371 Increase liability for vacant office space 1,005 Reduction of liability for lease payments (1,880) Other, net  (67) Balance as of December 31, 2010  $ 2,429 Minimum Future Rental Commitments  ($000) 2011  $ 19,398 2012  16,391 2013  14,279 2014  14,723 2015  14,296 Thereafter  74,458 Total  $ 153,545 ($000)  2010 2009  2008 Rent expense  $19,761 $ 18,842  $16,674 128