A landmark-based transformation approach to concurrency control in group editors

Operational transformation (OT) is a responsive and nonblocking concurrency control method widely-accepted in group editors. Correctness and performance are the basis of usefulness and usability of OT-based group editors. However, the correctness of previous OT algorithms depends on conditions that are very difficult to verify. In this paper we propose a novel landmark-based transformation (LBT) approach, its correctness no longer depending on those conditions and thus easy to prove. In addition, we give an example algorithm that significantly outperforms a state-of-the-art OT algorithm. This work reveals a more practical approach to developing OT algorithms.