This book constitutes the refereed proceedings of the 11th International Conference on Open Semantic Technologies for Intelligent Systems, OSTIS 2021, held in Minsk, Belarus, during September 16-18, 2021. The 20 full papers included in this book were carefully reviewed and selected from 46 submissions. The papers are focused on the development of flexible and compatible technologies that provide fast and high-quality construction of intelligent systems for various purposes.

This book constitutes the refereed proceedings of the 10th International Conference on Open Semantic Technologies for Intelligent System, OSTIS 2020, held in Minsk, Belarus, in February 2020. The 14 revised full papers and 2 short papers were carefully reviewed and selected from 62 submissions. The papers mainly focus on standardization of intelligent systems and cover wide research fields including knowledge representation and reasoning, semantic networks, natural language processing, temporal reasoning, probabilistic reasoning, multi-agent systems, intelligent agents.