+The directory system described in the previous chapter, are themselves
+contained within <em/distribution directories/. Every distribution is
+contained in the <tt/dists/ directory in the top-level of the Debian
+archive itself (the symlinks from the top-level directory to the
+distributions themselves are for backwards compatability and are
+deprecated).
+ <p>
+To summarize, the Debian archive has a root directory within an FTP
+server. For instance, at the mirror site,
+<ftpsite>ftp.us.debian.org</ftpsite>, the Debian archive itself is
+contained in <ftppath>/debian</ftppath>, which is a common location
+(another is <ftppath>/pub/debian</ftppath>).
+ <p>
+Within that archive root, the actual distributions are contained in
+the <tt/dists/ directory. Here is an overview of the layout:
+ <p>
+<example>
+<var>archive root</var>/dists/<var>distribution</var>/<var>section</var>/<var>architecture</var>/<var>subsection</var>/<var>packages</var>
+</example>
+
+Extrapolating from this layout, you know that to find the i386 base
+packages for the distribution <em/slink/, you would look in
+<ftppath>/debian/dists/slink/main/binary-i386/base/</ftppath>.
+
+ <sect1>Stable, unstable, and sometimes frozen
+ <p>
+There is always a distribution called <em/stable/ (residing in
+<tt>dists/stable</tt>) and one called <em/unstable/ (residing in
+<tt>dists/unstable</tt>). This reflects the development process of the
+Debian project.
+ <p>
+Active development is done in the <em/unstable/ distribution (that's
+why this distribution is sometimes called the <em/development
+distribution/). Every Debian developer can update his or her packages
+in this distribution at any time. Thus, the contents of this
+distribution change from day-to-day. Since no special effort is done
+to test this distribution, it is sometimes ``unstable.''
+ <p>
+After a period of development, the <em/unstable/ distribution is
+copied in a new distribution directory, called <em/frozen/. When that
+occurs, no changes are allowed to the frozen distribution except bug
+fixes; that's why it's called ``frozen.'' After another month or a
+little longer, the <em/frozen/ distribution is renamed to <em/stable/,
+overriding the old <em/stable/ distribution, which is removed at that
+time.
+ <p>
+This development cycle is based on the assumption that the
+<em/unstable/ distribution becomes <em/stable/ after passing a period
+of testing as <em/frozen/. Even once a distribution is considered
+stable, a few bugs inevitably remain--that's why the stable
+distribution is updated every now and then. However, these updates are
+tested very carefully and have to be introduced into the archive
+individually to reduce the risk of introducing new bugs. You can find
+proposed additions to <em/stable/ in the <tt/proposed-updates/
+directory. Those packages in <tt/proposed-updates/ that pass muster
+are periodically moved as a batch into the stable distribution and the
+revision level of the stable distribution is incremented (e.g., `1.3'
+becomes `1.3r1', `2.0r2' becomes `2.0r3', and so forth).
+ <p>
+Note that development under <em/unstable/ is continued during the
+``freeze'' period, since a new <em/unstable/ distribution is be
+created when the older <em/unstable/ is moved to <em/frozen/.
+Another wrinkle is that when the <em/frozen/ distribution is offically
+released, the old stable distribution is completely removed from the
+Debian archives (although you can still find it from servers which
+serve up older, obsolete distributions).
+ <p>
+In summary, there is always a <em/stable/ and an <em/unstable/
+distribution available, and the <em/frozen/ distribution shows up for
+a month or so from time to time.
+
+
+ <sect1>Experimental
+ <p>
+The <em/experimental/ distribution is a specialty distribution. It is
+not a full distribution in the same sense that `stable' and `unstable'
+are. Instead, it is meant to be a temporary staging area for highly
+experimental software where there's a good chance that the software
+could break your system. Users who download and install packages from
+<em/experimental/ are expected to have been duly warned. In short,
+all bets are off for the <em/experimental/ distribution.
+ <p>
+Developers should be very selective in the use of the
+<em/experimental/ distribution. Even if a package is highly unstable,
+it could well still go into <em/unstable/; just state a few warnings
+in the description. However, if there is a chance that the software
+could do grave damage to a system, it might be better to put it into
+<em/experimental/.
+ <p>
+For instance, an experimental encrypted file system should probably go
+into experimental. A new, beta, version of some software which uses
+completely different configuration might go into experimental at the
+maintainer's discretion. New software which isn't likely to damage
+your system can go into <em/unstable/.
+
+
+ <sect id="codenames">Release code names
+ <p>
+Every released Debian distribution has a <em/code name/: Debian 1.1 is
+called `buzz'; Debian 1.2, `rex'; Debian 1.3, `bo'; Debian 2.0,
+`hamm'; Debian 2.1, `slink'; and Debian 2.2, `potato'. There is
+also a ``pseudo-distribution'', called `sid' which is contains
+packages for architectures which are not yet officially supported or
+released by Debian. These architectures are planned to be integrated
+into the mainstream distribution at some future date.
+ <p>
+Since the Debian has an open development model (i.e., everyone can
+participate and follow the development) even the unstable distribution
+is distributed via the Internet on the Debian FTP and HTTP server
+network. Thus, if we had called the directory which contains the
+development version `unstable', then we would have to rename it
+to `stable' when the version is released, which would cause all FTP
+mirrors to re-retrieve the whole distribution (which is already very
+large!).
+ <p>
+On the other hand, if we called the distribution directories
+<em>Debian-x.y</em> from the beginning, people would think that Debian
+release <em>x.y</> is available. (This happened in the past, where a
+CD-ROM vendor built a Debian 1.0 CD-ROM based on a pre-1.0 development
+version. That's the reason why the first official Debian release was
+1.1, and not 1.0.)
+ <p>
+Thus, the names of the distribution directories in the archive are
+determined by their code names and not their release status (i.e.,
+`slink'). These names stay the same during the development period
+and after the release; symbolic links, which can be changed, are made
+to indicate the currently released stable distribution. That's why
+the real distribution directories use the <em/code names/ and symbolic
+links for <em/stable/, <em/unstable/, and <em/frozen/ point to the
+appropriate release directories.
+