For those out of the loop, PackageKit is the abstraction layer for management management systems and allows for application accesss over DBus. AppStream is the cross-distribution effort for powering Software Centers/Stores with common meta-data for information like ratings and screenshots. Lastly, Listaller is the cross-distribution third-party software installer built atop PackageKit and AppStream.
Read Matthias's blog post for all of the details but the key information comes down to:
- PackageKit 0.8.x is working out quite well with performance improvements -- even to the speed of using native distribution package management software.
- Most Linux distributions are using (or supporting) PackageKit except for Ubuntu.
- "The AppStream side doesn’t look incredibly great, but the situation is improving."
- The KDE PackageKit front-end (Apper) now has full support for AppStream and there's a GNOME Software component being developed for AppStream support too.
- Listaller is nearing a point of doing a release with a stable API and specifications.
- Only a few Linux distributions are packaging Listaller at this point.