Ignat, Claudia-LaviniaNorrie, Moira C.2017-04-152017-04-152003978-94-010-0068-0Research in collaborative editing tends to have been undertaken in isolation rather than as part of a general information or application infrastructure. Our goal is to develop a universal information platform that can support collaboration in a range of application domains. Since not all user groups have the same conventions and not all tasks have the same requirements, this implies that it should be possible to customize the collaborative editor at the level of both communities and individual tasks. One of the keys to customization is to use a structured rather than linear representation of documents that can be applied to both textual and graphical editors. In this paper, we propose the treeOPT (tree OPerational Transformation) algorithm that, relying on a tree representation of documents, applies the operational transformation mechanism recursively over the different document levels. Applications using this algorithm achieve better efficiency, the possibility of working at different granularity levels and improvements in the semantic consistency.enText10.1007/978-94-010-0068-0_17