- Pacer Infotec Inc.
- PADS Software Inc.
- Palmchip Corporation
- Palmchip interface IP
- Panel Level Packaging Consortium (PLC)
- Paradigm Works
- Parsec Software Inc.
- PCB Libraries Inc.
- PCB Matrix Corporation
- PDF Solutions
- Performance CAD
- Performance Signal Integrity, Inc.
- Performance-IP, LLC.
- Personal CAD Systems
- Pextra Corporation
- Philips Semiconductor
- Phoenix Technologies Ltd.
- Physware, Inc.
- PiE Design Systems Inc.
- Pinebush Technologies
- Plato Design Systems
- PLDA
- Pleiades Design and Test Technologies Inc.
- Plunify Pte Ltd
- Pollen Technology
- PolySpace Technologies
- Ponte Solutions Inc.
- Portable Stimulus Working Group (PSWG)
- PowerEscape, Inc.
- Praesagus, Inc.
- Precedence Inc.
- Precim Corp
- Precise Software Technologies Inc
- ProDesign Electronic GmbH
- Progressant Technologies, Inc.
- Project Technology Inc.
- Prolific, Inc.
- Promex Industries
- ProPlus Design Solutions, Inc.
- ProSoft Oy
- proteanTecs
- Protecode
- Protel International Pty, Ltd.
- Provis Corporation
- prpl foundation
- Pulsic
- Pyxis Technology
- Q Design Automation
- Q Point Technology
- QP Technologies