	December 31,			June 30,
	2021			2022
Computer and other related equipment	$	13,373		$	14,586
Purchased and internally developed software		2,483			2,899
Furniture and fixtures		1,271			1,271
Leasehold improvements		1,732			1,732
Construction in progress		769			773
	$	19,628		$	21,261
Less: Accumulated depreciation and amortization		(16,811	)		(17,495	)
Property and equipment, net	$	2,817		$	3,766

We capitalize certain software development costs incurred in connection with developing or obtaining computer software for internal use when both the preliminary project stage is completed and it is probable that the software will be used as intended. Capitalized software costs include (i) external direct costs of materials and services utilized in developing computer software, (ii) compensation and related benefits for employees who are directly associated with the software projects. Capitalized software costs are amortized on a straight-line basis when placed into service over the estimated useful life of the software, generally averaging three years. We capitalized software development costs of $623,000 for the six months ended June 30, 2022.

Depreciation and amortization expense related to property and equipment was approximately $687,000 and $679,000 for the six months ended June 30, 2021 and 2022, respectively. Depreciation and amortization expense related to property and equipment was approximately $328,000 and $361,000 for the three months ended June 30, 2021 and 2022, respectively.

	For the Six Months Ended						For the Three Months Ended
	2021			2022			2021			2022
Interest Income	$	2		$	12		$	-		$	9
Interest Expense & Foreign Currency		(32	)		(16	)		(19	)		8
Other		2,504			-			2,505			-
Total	$	2,474		$	(4	)	$	2,486		$	17