This book constitutes thoroughly revised, selected papers of the proceedings of the 6th International Workshop on Collaborative Agents Research and Development, CARE 2015 and the Second International Workshop on Multi-agent Foundations of Social Computing, MFSC 2015, held in Istanbul, Turkey, on May 4, 2015. Both Workshops were held in conjunction with AAMAS 2015.

The 5 revised full papers of CARE and the 7 full papers of MFSC presented were carefully selected from 14 CARE and 10 MFSC submissions. Both workshop address issues in relevant areas of social computing such as...