OTHER INTANGIBLE ASSETS

As of the dates indicated, other intangible assets are comprised of the following (in thousands):



	July 31, 2017							October 31, 2016
	Gross Intangible		Accumulated Amortization			Net Intangible		Gross Intangible		Accumulated Amortization			Net Intangible
Developed technology	$	341,255	$	(262,308	)	$	78,947	$	347,727	$	(248,128	)	$	99,599
In-process research and development	671		—			671		4,200		—			4,200
Patents and licenses	7,165		(6,473		)	692		7,165		(6,285		)	880
Customer relationships, covenants not to compete, outstanding purchase orders and contracts	334,642		(307,962		)	26,680		358,647		(316,615		)	42,032
Total other intangible assets	$	683,733	$	(576,743	)	$	106,990	$	717,739	$	(571,028	)	$	146,711

During the third quarter of fiscal 2017, certain fully amortized intangible assets of approximately $34.0 million were eliminated from gross intangible assets and accumulated amortization, with no corresponding impact to the income statement. These assets were primarily technology for products no longer being sold by Ciena.

As the result of the acquisition of the high-speed photonics components assets from TeraXion and its wholly-owned subsidiary on February 1, 2016, Ciena had recorded in-process research and development projects acquired as indefinite-lived intangible assets. Upon completion of the projects, the assets will be amortized on a straight-line basis over the expected economic life of the assets. In the third quarter of fiscal 2017, Ciena placed into service $3.5 million of developed technology, which will be amortized over the expected economic life of five years.

The aggregate amortization expense of intangible assets was $39.7 million and $59.4 million for the first nine months of fiscal 2017 and 2016, respectively. Expected future amortization of intangible assets for the fiscal years indicated is as follows (in thousands):



Period ended October 31,
2017 (remaining three months)	$	5,993
2018	23,386
2019	22,839
2020	21,812
2021	18,878
Thereafter	13,411
	$	106,319	⁽¹⁾

(1) Does not include amortization of in-process research and development, as estimation of the timing of future amortization expense would be impractical.