Collaboration has become a key feature of modern software, allowing teams to work together effectively in real-time while in different locations. In order for a user to communicate their intention to several distributed peers, computing devices must exchange high-frequency updates with transient metadata like mouse position, text range highlights, and temporary comments. Current peer-to-peer awareness solutions have high time and space complexity due to the ever-expanding logs that each client must maintain in order to ensure robust collaboration in eventually consistent environments. This paper proposes an awareness Conflict-Free Replicated Data Type (CRDT) library that provides the tooling to support an eventually consistent, decentralized, and robust multi-user collaborative environment. Our library is tuned for rapid iterative updates that communicate fine-grained user actions across a network of collaborators. Our approach holds memory constant for subsequent writes to an existing key on a shared resource and completely prunes stale data from shared documents. These features allow us to keep the CRDT's memory footprint small, making it a feasible solution for memory constrained applications. Results show that our CRDT implementation is comparable to or exceeds the performance of similar data structures in high-frequency read/write scenarios.

This thesis compares different approaches of creating a collaborative editing application using different methods such as OT, CRDT and Locking. After a comparison between these methods an implementation based on CRDT was done. The implementation of a collaborative graphical network was made such that consistency is guaranteed. The implementation uses the 2P2P-Graph which was extended in order to support moving of nodes, and uses the client-server communication model. An evaluation of the implementation was made by creating a time-complexity and a space complexity analysis. The result of the thesis includes a comparison between different methods and by an evaluation of the Extended 2P2P-Graph.