Explore a comprehensive conference talk on the Ethos operating system's distributed mandatory type system, Etypes. Delve into the key properties of Etypes, including object type declaration, prevention of ill-formed data writing and reading, and programmer-defined data types. Examine the generality of Etypes through the conversion of Chomsky normal form grammars into Ethos types. Investigate the convenience aspect of Etypes and its impact on program crafting. Learn about a sample distributed program utilizing Etypes techniques. Gain insights into the future of Etypes, including preprocessor development and open-source initiatives.