Systems and methods are disclosed for synchronizing a document markup modification across a plurality of devices. One method comprises subscribing to one or more events occurring in a first document markup application, the first document markup application being a first thin client application, and receiving a notification indicating a modification to a document markup in the first document markup application. A cross-compatible markup object associated with the modified document markup may be extracted and transmitted to a second document markup application, the second document markup application being a second thin client application.