- A security framework
- A dependency framework
- No extra baggage
- request reading or writing an existing file, selected by the user
- request writing a new file
- suggest a url to visit (optionally with post data).
For dependencies, programs should specify urls (possibly self-certifying) of code that they depend on. All code could be cached locally or downloaded anew as desired. This is in the spirit of package management approaches without "side effects", like Nix and Zero Install.
Once there's a sufficiently powerful dependency framework, we need not hard code any dependency on "standard software" like programming languages or gui toolkits. Programs could be transported in llvm bytecode.
Implicitly trusted programs could be subject to phishing attacks just as websites currently are, so it would be desirable to have some sort of petnames scheme, as well as a spoof-resistant UI for distinguishing programs.