- PALUNO - The Ruhr Institute for Software Technology
- PEPITe
- Peking University [Beijing]
- Pennsylvania Commonwealth System of Higher Education (PCSHE)
- Peoples Friendship University of Russia [RUDN University]
- Philips Healthcare [Eindhoven]
- Philips Research Europe [The Netherlands]
- Physical and Life Sciences Directorate [Livermore]
- Politecnico di Milano [Milan]
- Politecnico di Torino = Polytechnic of Turin
- Pontificia Universidad Javeriana
- Poznan University of Technology
- Prague University of Economics and Business
- Preuves et Langages
- Preuves, Programmes et Systèmes
- PrimeKey Solutions AB [Solna, Sweden]
- Privacy Models, Architectures and Tools for the Information Society
- Pro4u Open Source AB [Stockholm]
- Programamos [Sevilla]
- Prologue
- Proof search and reasoning with logic specifications
- Providence College