Looks good and well thought out. A couple of questions: * ByteInput and ByteOutput - could they be compatible with org.jboss.cache.io.ByteBuffer? Essentially this class is an extension of org.jgroups.util.Buffer, which provides direct access to a byte array. I'd hate to have to copy things around to use these new interfaces. * StreamHeader is useful for me since I need to add version bits to the stream such that the receiving end can use the appropriate marshaller implementation based on the version. * How are ObjectMarshallers selected? Based on the class info from the ClassMarshaller? Could this be ClassMarshaller + some token from the StreamHeader? (see previous point for reason why) * Pooling MOIS and MOOS - probably will have to happen due to the cost of constructing these, and if they are reused, why would you discard the Object and Cache Marshallers from the Marshaller? * Reference counting. Do you propose any sort of ref counting, if I were to write the same instance to the stream multiple times? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4169077#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...