Software



	As of December 31,
	2014			2013
Software	$	812.1		$	457.7
Accumulated amortization	(219.4		)	(114.2		)
Software, net	$	592.7		$	343.5

During the fourth quarter of 2014, we recorded $308.3 million of software associated with our acquisition of Bally. During the fourth quarter of 2013, we recorded $257.8 million of software associated with our acquisition of WMS including $201.2 million of intellectual property. In the years ended December 31, 2014 and 2013, we capitalized $47.9 million and $37.9 million, respectively, of software systems development costs. The total amount charged to amortization expense for amortization of software costs was $95.7 million, $39.6 million and $28.0 million for the years ended December 31, 2014, 2013 and 2012, respectively.

During the year ended December 31, 2014, we recorded accelerated amortization expense of $3.8 million related to software in our gaming business for a product we are discontinuing. During the year ended December 31, 2013, we recorded accelerated amortization expense of $8.0 million related to the write-down of certain development costs including $4.6 million related to software for a line of gaming machines we discontinued as a result of our reorganization plans and $3.4 million related to software in our gaming business for a product we are discontinuing. During 2012, we recorded $3.1 million related to the write-down of certain hardware development costs in our licensed brands business.