Note 7 – Intangibles

Intangibles at December 31, 2011 and 2010 were as follows (in thousands):


				2011							2010
		Gross					Net		Gross					Net
		Carrying		Accumulated			Carrying		Carrying		Accumulated			Carrying
		Amount		Amortization			Amount		Amount		Amortization			Amount
Capitalized software development costs	$	53,086	$	(29,606	)	$	23,480	$	40,481	$	(16,217	)	$	24,264
Acquired technology		67,918		(32,210	)		35,708		35,634		(25,017	)		10,617
Patents		21,875		(7,992	)		13,883		20,790		(6,312	)		14,478
Other		24,614		(13,819	)		10,795		14,059		(10,602	)		3,457
	$	167,493	$	(83,627	)	$	83,866	$	110,964	$	(58,148	)	$	52,816

Software development costs capitalized during 2011, 2010 and 2009 were $12.6 million, $16.5 million and $13.3 million, respectively, and related amortization was $13.4 million, $10.7 million and $9.1 million, respectively. Included in these capitalized costs for the years ended December 31, 2011, 2010 and 2009, were costs related to stock based compensation of $539,000, $719,000 and $734,000, respectively.

Amortization of capitalized software development costs is computed on an individual product basis for those products available for market and is recognized based on the product's estimated economic life, generally three years. Acquired intangible assets which include acquired technology and other are amortized over their useful lives, which range from three to eight years. Patents are amortized using the straight-line method over their estimated period of benefit, generally ten to seventeen years. Total intangible assets amortization expenses were $25.5 million, $17.9 million and $16.5 million for the years ended December 31, 2011, 2010 and 2009, respectively.

Capitalized software development costs, acquired technology, patents and other have weighted-average useful lives of 2.1 years, 2.6 years, 6.9 years, and 2.4 years, respectively, as of December 31, 2011. The estimated future amortization expense related to intangible assets as of December 31, 2011 is as follows:


		Amount
		(in thousands)
2012	$	26,635
2013		20,192
2014		13,953
2015		9,523
2016		5,172
Thereafter		8,391
	$	83,866

The overall increase in our acquired technology and other intangible assets can be attributed to our acquisitions of AWR Corporation and Phase Matrix Inc. See Note 15 – Acquisitions of Notes to Consolidated Financial Statements for additional discussion related to these acquisitions.