- CLMS UK Ltd
- COMSATS Institute of Information Technology [Islamabad]
- CSIRO Computational Informatics
- California State University [Fresno]
- Catholic University of Leuven = Katholieke Universiteit Leuven
- Center for Advanced Studies [IBM CAS Canada]
- Center for Industrial Production
- Center of Operation Research and Econometrics [Louvain]
- Central University of Finance and Economics [Beijing]
- Centre Génie Industriel
- Centre National de la Recherche Scientifique
- Centre National d’Études Spatiales [Paris]
- Centre de Recherche Public Henri-Tudor [Luxembourg]
- Centre de Recherche en Informatique de Paris 1
- Centre for Research and Technology Hellas
- Centre for Research and Technology Hellas [Athènes]
- Centre for Secure, Intelligent and Usable Systems [Brighton]
- Centro de Computação Gráfica
- Centro de Informatica UFPE [Recife]
- Centro de Investigación en Métodos de Producción de Software
- Chalmers University of Technology [Gothenburg, Sweden]
- Chalmers University of Technology [Göteborg]
- Chasquis Consulting
- China Unicom
- Chinese Culture University [Taipei]
- Chinese PLA General Hospital
- Chonbuk National University
- Chongqing Technology and Business University
- Chongqing University [Chongqing]
- Chongqing University of Technology
- Christian-Albrechts-Universität zu Kiel = Christian-Albrechts University of Kiel = Université Christian-Albrechts de Kiel
- City University London
- Collibra SA-NV [Brussels]
- Commitment AS [Lysaker]
- Commonwealth Scientific and Industrial Research Organisation [Canberra]
- Consult Hyperion
- Corvinus University of Budapest
- Craig School of Business [California]