libappstream4 binary package in Ubuntu Focal amd64

 AppStream is a metadata specification, allowing to write metadata for
 software projects in a standardized format. This allows software centers
 to display useful information for not installed software, as well as
 determining software the user might want to install (e.g. to open an
 unknown file type or to make missing firmware available).
 .
 This package contains a GObject-based library to access AppStream
 services, like the software component metadata pool.
 It also contains functions for reading, writing and transforming AppStream
 metadata.

Source package