Envoy is an "open and display things" library. It provides an interface for storing file associations and launching files based on those associations. This comes with a wrapper program to enable desktop users to benefit from the file associations without developers adding explicit support. It also supports opening any URI transparently, as long as the corresponding protocol support exists: applications that want simple read (and write, depending on the protocol) access to files, wherever they are, can use the envoy API to do so.
