- Semiconductor Manufacturing International Corp.
- Semifore, Inc.
- Sente Inc.
- Sequence Design
- SETO Software GmbH
- Shiva Multisystems Corp.
- Si2
- Si2 Open3D Technical Advisory Board
- Sibridge Technologies
- SiCAD Inc.
- Sidense Corp.
- Siemens EDA
- Sierra Design Automation
- Sigma-C Software AG
- Signal Integrity Software, Inc.
- Signetics Corporation
- Sigrity, Inc.
- SilabTech Pvt Ltd.
- Silc Technologies
- Silerity Inc
- Silexica
- Silicon Architects
- Silicon Canvas, Inc.
- Silicon Cloud International Pte Ltd
- Silicon Compiler Systems Corp.
- Silicon Compilers Inc.
- Silicon Creations, LLC
- Silicon Design Labs
- Silicon Design Solutions
- Silicon Forest Research inc.
- Silicon Frontline Technology, Inc.
- Silicon Logic Engineering
- Silicon Metrics Corporation
- Silicon Perspective Corp.
- Silicon Solutions Corporation
- Silicon Sorcery
- Silicon Storage Technology, Inc.
- Silicon Valley Research
- Silicon West
- SiliconBlue Technologies Corporation
- SiliconGate LDA
- Siliconware Precision Industries
- Silvaco, Inc.
- Silvar-Lisco, Inc.
- Simon Software
- Simpleware
- Simplex Solutions
- Simucad Design Automation Inc.
- Simucad Inc.
- Simulation Technologies Corp
