The idea does not sound to me like it is fully formed. But it reminds me of "datatypes" in Amiga OS 3.0. A datatype was a kind of plugin that could be used to

The idea does not sound to me like it is fully formed. But it reminds me of "datatypes" in Amiga OS 3.0. A datatype was a kind of plugin that could be used to decode/encode a specific file format. You could just drag the datatype file icon into the "DEVS:Datatypes" directory, and it would become available to all programs that requested datatypes for a specific category of file formats. Thanks to Datatypes, Amiga OS was the first OS that got support for the PNG file format in all web browsers on the platform.