This book constitutes the proceedings of the 20th Collaboration Researchers' International Working Group Conference on Collaboration and Technology, held in Santiago, Chile, in September 2014.The 16 revised papers presented together with 18 progress papers and 3 invited talks were carefully reviewed and selected from 49 submissions. The papers published in proceedings of this year's and past CRIWG conferences reflect the trends in collaborative computing research and its evolution. There was a growing interest in social networks analysis, crowdsourcing and computer support for large communities in general. A special research topic which has been traditionally present in the CRIWG proceedings has been collaborative learning.