Elliotte Rusty Harold on EXI, the Efficient XML Interchange (EXI) Format:
Whatever the EXI format is, it’s not XML and using the name “XML” to describe it an attempt by people who want something very different from XML to trade on XML’s good name. If EXI were really a good idea, it could succeed on its own merits without pretending to be something it’s not. I guess the working group members don’t really believe in it though.
I agree that it’s not XML, but it’s interesting to me. EXI is for streaming Infosets — the data model XML is a representation of — with (hopefully) much less parsing overhead. I haven’t looked at EXI until now, but I wouldn’t write it off too quickly. One thing I did notice was the 2 different grammar systems. One is just XML-based and it “evolves” as namespaces and prefixes occur. The other is “schema-informed”, which means the stream has some schema information (XSD, RELAX, etc.) encoded and the grammar stays static. Could be nice.