14. A non-transitory computer-readable storage medium having stored thereon instructions that, upon execution by a first computing device, cause the first computing device at least to: maintain, on the first computing device, a first collection of change descriptors representative of changes to a first data state; send, to another computing device, a first one or more change descriptors from the first collection, the first one or more change descriptors based at least in part on a first value indicative of a last position of change descriptors stored in both the first collection and in a second collection of change descriptors maintained on a second computing device; receive a second one or more change descriptors, the second one or more change descriptors based at least in part on resolving conflicts between the first one or more change descriptors and changes to the first data state made on the second computing device; append the second one or more change descriptors to the first collection; and update the first value based at least in part on a last position of a change descriptor in the first collection subsequent to appending the second one or more change descriptors.
14. A non-transitory computer-readable storage medium having stored thereon instructions that, upon execution by a first computing device, cause the first computing device at least to: maintain, on the first computing device, a first collection of change descriptors representative of changes to a first data state; send, to another computing device, a first one or more change descriptors from the first collection, the first one or more change descriptors based at least in part on a first value indicative of a last position of change descriptors stored in both the first collection and in a second collection of change descriptors maintained on a second computing device; receive a second one or more change descriptors, the second one or more change descriptors based at least in part on resolving conflicts between the first one or more change descriptors and changes to the first data state made on the second computing device; append the second one or more change descriptors to the first collection; and update the first value based at least in part on a last position of a change descriptor in the first collection subsequent to appending the second one or more change descriptors. 19. The computer-readable storage medium of claim 14 , wherein the first one or more change descriptors comprises a reference to an element of the data state, the reference comprising a position of a change descriptor contained in the first collection.