- Q Design Automation
- Q Point Technology
- QP Technologies
- QPX GmbH
- Quad Design Technology, Inc.
- Quadric
- Quadtree Software Corporation
- Qualcomm Incorporated
- Qualis, Inc.
- Quickturn Design Systems, Inc.
- R3Logic, Inc.
- Racal Redac
- Racal Redac – VHDL simulator
- Racal Redac SilcSyn
- Radiant Design Tools, Inc.
- Rambus, Inc.
- Random Logic Corporation
- RAPID
- RaveSim, Inc.
- RAVIcad Inc.
- Ready Systems
- Real Intent, Inc.
- Redwood Design Automation
- Renesas Electronics
- ReShape Inc
- RevoSys Inc.
- Right Track CAD Corp.
- Rio Design Automation
- Riscure
- RivieraWaves
- Rocketick
- Router Soutions, Inc.
- Royal Digital Centers, Inc.
- RSoft Design Group Inc.
- Runtime Design Automation
- S2C Inc.
- S3 Group
- Sabio Labs
- Safelogic
- Sagantec
- Sage Design Automation, Inc.
- Samsung Foundry
- Sand Microelectronics
- Sandburst
- Sandwork Design, Inc.
- Sankalp Semiconductor
- SCALD Corporation
- SciFace Software GmbH & Co. KG
- SDA Systems Inc.
- Sedco
