This book constitutes the refereed proceedings of the 25th International Conference, CRIWG+CollabTech 2019, held in Kyoto, Japan in September 2019. The 12 full papers presented in this book together with 8 work-in-progress papers were carefully reviewed and selected from 28 submissions, and the program also included an invited talk. This year presented a merger of the CRIWG and CollabTech conferences after having been jointly held since 2014. The papers published in this proceedings focus on innovative collaboration technologies and social computing.