Software management on Linux is traditionally done using packages, although desktop users are more interested in applications instead and do not care much about how something is packaged. Also, users often want to install software which is not available in the repositories (e.g. unpackaged stuff, as well as new versions of applications), without having to upgrade the whole distribution. AppStream provides a solution for application-centric software management using the existing package-managers, by providing extra metadata for packages. This allows developers to create cross-distro application-centers, like GNOME-Software or Apper. Listaller extends the package manager with the ability to install 3rd-party applications, which are not (yet) in the distribution's repositories. It builds on top of the AppStream specs and focuses on integration, so the installation process is completely transparent for users, and Listaller-installed applications can be managed with existing software-management tools. Because software from 3rd-party sources is a potential security risk, Listaller also tries to give users a hint if they can trust a certain application, and includes sandboxing for these applications. Both projects rely heavily on metadata provided by upstream projects and distributions. This talk will explain the concepts of AppStream and Listaller, which new metadata needs to be added and why as well as how distributions can make a software-center available for their users. If the time allows it, the talk will also highlight the problems we had with the AppStream project in the first place and how we could improve cross-distribution collaboration in general.