What is AppStream?
AppStream is a cross-distribution effort for enhancing the way we interact with the software repositories provided by (Linux) distributions by standardizing software component metadata.
It provides the foundation to build software-center applications, by providing metadata necessary for an application-centric view on package repositories. AppStream additionally provides specifications for things like an unified software metadata database, screenshot services and various other things needed to create user-friendly application-centers for (Linux) distributions.
You can find the latest version of the AppStream specification at freedesktop.org/software/appstream/docs/.
The specification describes the AppStream upstream XML format which is used by upstream software authors to describe the software component (application, firmware, font, ...) they provide, as well as the AppStream distro XML format that is used by distributions to ship the metadata in bundled and processed form to their users.
The specification now also contains a description of DEP-11, which is a YAML-based version of the distro XML specification used by Debian and its derivatives.
- General discussion is happening on the distribution mailing list at Freedesktop
- AppStream Spec & Library development: github.com/ximion/appstream
There is also a separate project called appstream-glib, implementing the AppStream specification as well, which is used primarily at GNOME. It provides a distro-metadata generator, which distributions can use to provide their distro-XML file.
If you are looking for the previous information found on this page, including the meeting notes and resources produced during the initial AppStream meeting in 2011, you may look at the attic.