This category, although originally intended for companies that manufacture computer hardware or publish computer software, may need to be reconsidered.
Computer hardware manufacturers:
Burroughs: Instruction-set architecture based on the Algol Language.
CDC (Control Data): Designed the earliest Super Computers.
Cray (Cray Research): Designed even faster Super Computers.
GE (General Electric): Original platform for the Multics Os and the Basic Language.
Honeywell.
Univac.
Xerox and Sigma Data Systems (Xerox Corporation).
Computer software publishers:
Aradial Technologies - www.aradial.com 
- Authentication Servers.
Some computer-related think tanks:
My immediate interest was focused on "IBM and the Seven Dwarfs", for their relevance to early computer hardware and software history.
-- Clay Phipps
See original on c2.com