Google Docs collaborative editing using OT in [part 1][part-1], [part 2][part-2], and [part 3][part-3]. [part-1]: https://drive.googleblog.com/2010/09/whats-different-about-new-google-docs_21.html [part-2]: https://drive.googleblog.com/2010/09/whats-different-about-new-google-docs_22.html [part-3]: https://drive.googleblog.com/2010/09/whats-different-about-new-google-docs.html