6. Debt

Capital Lease Arrangements

Since 2013, the Company has entered into capital lease arrangements with an equipment manufacturer to finance acquisitions of computer equipment. These leases have effective annual interest rates ranging from 5.8% to 6.0%, and carry terms of between 36 to 48 months. At the end of the lease periods, the Company has the option to purchase the underlying equipment at the estimated fair market value, or for a nominal amount in some cases. As of June 30, 2016 and December 31, 2015, the net book value of the equipment under these capital leases was $2,092 and $2,446, respectively, and the remaining principal balance payable was $2,333 and $2,700, respectively.

Revolving Credit Facility

In July 2015, the Company entered into an amendment to its existing loan and security agreement pursuant to which Silicon Valley Bank agreed to increase the revolving credit facility of up to the lesser of $20,000 or 80% of the Company’s eligible accounts receivable. Also, the expiration date of the revolving credit facility was extended to July 31, 2017, and the annual interest rate was amended to (a) the prime rate or (b) the London interbank offered rate then in effect, plus a margin of 2.75%, payable on a monthly basis. The amendment contains affirmative and negative covenants, including covenants related to the delivery of financial and other information, the maintenance of certain financial covenants, as well as limitations on dispositions, changes in business or management, mergers or consolidations, dividends and other corporate actions. The revolving credit facility was amended further in February 2016 to update the terms of certain covenants. No amounts were outstanding pursuant to the revolving credit facility as of June 30, 2016 and December 31, 2015.

The maturities of all outstanding debt, including the capital lease arrangements, as of June 30, 2016, are as follows:

Year ending
2016	$	447
2017		663
2018		702
2019		490
2020		31
		2,333
Less:
Current portion		(768	)
Discount on long-term debt		(28	)
Noncurrent portion of debt	$	1,537