- Synplicity, Inc.
- Synthesia AB
- SysChip Design Technologies
- Systems & Networks, Inc.
- Systems Science Inc.
- Systems Science, Inc.
- Systolic Technology Ltd.
- Tabulating Machine Company
- Tality Corp
- Tangent Systems Corporation
- Tanner EDA
- Tanner Research, Inc.
- Taray Inc.
- Target Compiler Technologies N.V.
- TASKING inc.
- TEAM Corporation
- Techniques Nouvelle d’Informatique SA
- Technology Modeling Associates Inc.
- Techspert
- Teja Technologies
- Teklatech
- Tektronix CAE and CASE Divisions
- Tektronix debug IP
- Tektronix, Inc.
- TEL (Tokyo Electron)
- Tela Innovations
- Telesis Systems Corp
- Telos Venture Partnership
- Tempus Fugit, Inc.
- Tenison Design Automation
- Tensilica
- Teradyne Corporation
- TeraRoute LLC
- Test and Verification Solutions Limited
- Test Design Automation group of IBM
- Tharas Systems, Inc.
- The Silicon Group, Inc.
- THEDA electronic design software
- Tiempo
- Tignis
- TIMA laboratory
- Timing Designer Technology
- Timing Designer Technology of Forte
- Titan Corporation
- TOOL Corporation
- Tool-sha Corporation
- Tower Semiconductor, Ltd.
- TowerJazz
- Transcendent Design Technology, Inc.
- Transcription Enterprises, Inc.
