Method, apparatus and system for data sharing in runtime systems are described. A set of data objects is identified, where each data object in the set of data objects comprises a reference to runtime metadata about the data object in a first runtime system. For each data object in the set of data objects, the reference to the runtime metadata in the data object is replaced with a proxy. The set of data objects is transmitted to a second runtime system. The transmitting of the set of data objects includes replacing the proxy with the reference to the runtime metadata for each of the set of data objects transmitted to the second runtime system. Further, a shared memory is associated with the first runtime system and the second runtime system such that the first and second runtime systems share us information at the shared memory.