1. A system comprising: a first computing device configured to maintain a first collection of ordered change descriptors representative of changes to a first data state, the first collection representing a version of the first data state, the first computing device configured at least to: send a first one or more change descriptors from the first collection to another computing device, the first one or more change descriptors based at least in part on a first copy of a value indicative of a last ordinal position of change descriptors stored in both the first collection of change descriptors and in a second collection of change descriptors maintained by a second computing device; receive a second one or more change descriptors from the another computing devices, 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 copy of the value based at least in part on a last ordinal position of a change descriptor in the first collection subsequent to appending the second one or more change descriptors.