Forrester
Forrester research, inc. (nasdaq: forr) is an independent technology and market research company that provides pragmatic and forward-thinking advice to global leaders in business and technology. since 1983, forrester has been making leaders successful every day through its proprietary research, consulting, events, and peer-to-peer executive programs.
http://www.forrester.com/
Gartner
Gartner delivers the technology-related insight necessary for our clients to make the right decisions every day
http://www.gartner.com/init
Idc
Idc
http://www.idc.com/
Ovum
Advising on the commercial impact of technology and market changes in telecoms, software and it services
http://www.ovum.com/
W&gs
Workflow and groupware stratégies provide consulting on document management software systems, workflow management software, knowledge management services, and business process management software.
http://www.wngs.com/