

	December 31, 2019
	Cost $	Accumulated amortization $	Net book value $
Acquired technology	161,643	17,332	144,311
Software development costs	27,489	16,690	10,799
Acquired customer relationships	8,435	1,016	7,419
Purchased software	6,973	5,639	1,334
Other intangible assets	4,120	701	3,419
	208,660	41,378	167,282



	December 31, 2018
	Cost $	Accumulated amortization $	Net book value $
Acquired technology	15,556	7,875	7,681
Software development costs	24,963	9,226	15,737
Acquired customer relationships	495	346	149
Purchased software	6,973	4,503	2,470
Other intangible assets	591	556	35
	48,578	22,506	26,072

Internal software development costs of $2,526 and $12,666 were capitalized during the years ended December 31, 2019 and 2018, respectively, and are classified within software development costs as an intangible asset. Amortization expense related to the capitalized internally developed software was $7,464 and $3,832 for the years ended December 31, 2019 and 2018, respectively, and is included in cost of revenues, sales and marketing and general and administrative expenses in the accompanying Consolidated Statements of Operations and Comprehensive Loss.

The following table illustrates the classification of amortization expense related to intangible assets in the Consolidated Statements of Operations and Comprehensive Loss:



	Years ended
	December 31, 2019 $	December 31, 2018 $
Cost of revenues	17,535	9,720
Sales and marketing	998	252
Research and development	266	60
General and administrative	73	109
	18,872	10,141



Fiscal Year	Amount $
2020	30,358
2021	22,152
2022	18,008
2023	17,706
2024	17,384
Thereafter	61,674
Total	167,282