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<chapter id="chap-AppStream-About">
<title>About AppStream</title>
<section id="about-whatis">
<title>What is AppStream?</title>
<para>
AppStream is a cross-distro effort for building Software-Center applications and enhancing metadata provided by software components.
It provides specifications for meta-information which is shipped by upstream projects and can be consumed by other software. The meta-information
includes data which is interesting to display in software centers and is mainly useful for end-users, as well as descriptions about the public
interfaces a software component provides, which is mainly useful for developers, 3rd-party software installers and for automatically installing
missing components on a distribution, for example missing firmware.
</para>
<para>
Distributors provide metadata as well, which describes all components available in a software repository. That data is composed of the upstream-metainfo
and some other sources.
AppStream also provides specifications for things like a screenshot-service, application ratings & reviews etc.
All AppStream distro-repository data is stored in a Xapian database, which then contains information about all available components in the distribution's
software repositories.
</para>
<para>
All parts of AppStream are distro-agnostic (with exception to some metadata which is used to generate the Xapian application cache), and therefore
AppStream makes it possible to build distro-agnostic application management tools.
</para>
<section>
<title>Architecture</title>
<para>
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</section>
</section>
</chapter>
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