What are the well-known IT companies in Canada?

Greo Products Inc, ISM-BC Corp, Seagate Software, Sierra Wireless Inc, PMC-Sierra Inc, Infowave Wireless Messaging Inc, QLT phototherapy company, MacDonald Dettwiler and Associates、Prologic Corp .、Pivotal Corp .、intelligence Works Inc .、Glenayre、Angiotech pharma ceuticals Inc .、 Benchmark Technologies Inc, B.C. Study Inc. and Electronic Arts (Canada) Inc