16.1.5 AppData - freedesktop.org application description

This file format is specified in https://www.freedesktop.org/software/appstream/docs/.

RPMs
appdata-tools, appstream, libappstream-glib, libappstream-glib-builder
Ubuntu packages
appdata-tools, appstream, libappstream-glib-dev
File extension
appdata.xml, metainfo.xml
Extractor
xgettext, intltool-extract, itstool