• SIXX
• XML serializer runs on various Smalltalk dialects. StOMP borrows lots of hook methods from SIXX.
• SRP (State Replication Protocol)
• Multi-dialect binary serializer which supports data interchangeability and class shape changes. StOMP has similar design goals. SRP data is self-described and has some overheads, but data size tends to be smaller than StOMP when handling big object graph.
• Fuel
• A newly-introduced binary serializer for Pharo. Clustered serialization format enables faster materialization than other serializers(see FuelBenchmarks page). Fuel is suitable if your application reads data frequently. 
• Xtreams
• Generalized stream/iterator framework. Xtream has its own serializer (marshaller) but it is also possible to plug other serializers into Xtream. StOMP-Xtreams package is available for the integration with Xtream. StOMP can be plugged into Xtream as a marshaller.

About MessagePack: