This U.S. industry comprises establishments primarily engaged in writing, modifying, testing, and supporting software to meet the needs of a particular customer.

Cross-References. Establishments primarily engaged in--

• Publishing packaged software--are classified in Industry 511210, Software Publishers; and
• Planning and designing computer systems that integrate computer hardware, software, and communication technologies, even though such establishments may provide custom software as an integral part of their services--are classified in U.S. Industry 541512, Computer Systems Design Services.