The Denali Group Analysis of information technology products. Free downloads of summary reviews. Detailed reviews available for purchase. http://www.sellmorenow.com/

Aberdeen Group Research and analysis of information technology companies and products. Many free downloads. Custom consulting services. http://www.aberdeen.com

Forrester Research Research and analysis information technology companies, products, and services, and of many specific industries. Many free downloads. Free newsletters. Custom research. http://www.forrester.com/

Gartner Group Research and analysis of information technology companies, products, and services, and of several industry sectors. Custom research and consulting services. Events and conferences. http://www.gartner.com

Giga Information Group Research and analysis of information technology products and services. Custom research and consulting services. Events and conferences. http://www.gigaweb.com/

AMR Research Central Research and analysis of information technology companies, products, and industry trends. Free newsletters. http://www.amrresearch.com

Meta Group Research and analysis of information technology products. Organizes events. Custom research and consulting services. http://www.metagroup.com/

International Data Corporation Research of information technology companies and markets. Free newsletters. Custom consulting services. http://www.idc.com

Technology Evaluation Research of information technology products. Some free downloads and newsletters. http://www.technologyevaluation.com

Butler Group Research and analysis of information technology covering products, services, and companies. Organizes events. Some free downloads. Custom consulting services. European and Australian base. http://www.butlergroup.com/

Ovum Research and analysis of information technology companies, products, and services. Organizes events. Some free downloads. Custom consulting services. European based. http://www.ovum.com/

Idate Research and analysis of telecommunications, Internet, and media companies. Organizes events. Free downloads. Custom consulting services. http://www.idate.org

Robert Frances Group Analysis of information technology companies and services. http://www.rfgonline.com

Yankee Group Research and analysis of information technology companies, products and services, and specific industry sectors. Organizes events. http://www.yankeegroup.com

Differentia LLC Research and analysis, primarily of voice technologies. Custom consulting services. http://www.differentia.com

Ventana Research Research and analysis of information technology companies and products. Many free downloads. Custom consulting services. http://www.ventanaresearch.com

Juniper Research Research, analysis and reporting of telecommunications technologies, markets and issues. Providers of research reports, consultancy and free white papers. http://www.juniperresearch.com/

Deep-Insight Web-based, customer and employee satisfaction and relationship management assessment services and software. http://info.deep-insight.com/