Just to give my view on third party extensions… I think it should be installed separately from the .mf file, requiring the user to explicitly download and install a separate executable. Reason being I see the main value of this being the ability to ultimately get web browser support - and then security becomes an issue. There is no way that you can allow arbitrary code in a web browser loaded app, as any malicious website could destroy you once the plugin is installed, so I think the ‘standard’ for these .mf files should be consistent in not supporting such extensions. Yeah, its not ideal, but if this web capability comes into being then security has to come first.