rec {

  # Content-addressable Nix mirrors.
  hashedMirrors = [
    http://tarballs.nixos.org
  ];

  # Mirrors for mirror://site/filename URIs, where "site" is
  # "sourceforge", "gnu", etc.

  # SourceForge.
  sourceforge = [
    http://prdownloads.sourceforge.net/
    http://heanet.dl.sourceforge.net/sourceforge/
    http://surfnet.dl.sourceforge.net/sourceforge/
    http://dfn.dl.sourceforge.net/sourceforge/
    http://mesh.dl.sourceforge.net/sourceforge/
    http://ovh.dl.sourceforge.net/sourceforge/
    http://osdn.dl.sourceforge.net/sourceforge/
    http://kent.dl.sourceforge.net/sourceforge/
  ];

  # GNU (http://www.gnu.org/prep/ftp.html).
  gnu = [
    # This one redirects to a (supposedly) nearby and (supposedly) up-to-date
    # mirror.
    http://ftpmirror.gnu.org/

    http://ftp.nluug.nl/pub/gnu/
    http://mirrors.kernel.org/gnu/
    ftp://mirror.cict.fr/gnu/
    ftp://ftp.cs.tu-berlin.de/pub/gnu/
    ftp://ftp.chg.ru/pub/gnu/
    ftp://ftp.funet.fi/pub/mirrors/ftp.gnu.org/gnu/

    # This one is the master repository, and thus it's always up-to-date.
    http://ftp.gnu.org/pub/gnu/
  ];

  # GCC.
  gcc = [
    ftp://ftp.nluug.nl/mirror/languages/gcc/
    ftp://ftp.fu-berlin.de/unix/languages/gcc/
    ftp://ftp.irisa.fr/pub/mirrors/gcc.gnu.org/gcc/
    ftp://gcc.gnu.org/pub/gcc/
  ];

  # GnuPG.
  gnupg = [
    ftp://gd.tuwien.ac.at/privacy/gnupg/
    ftp://gnupg.x-zone.org/pub/gnupg/
    ftp://ftp.gnupg.cz/pub/gcrypt/
    ftp://sunsite.dk/pub/security/gcrypt/
    http://gnupg.wildyou.net/
    http://ftp.gnupg.zone-h.org/
    ftp://ftp.jyu.fi/pub/crypt/gcrypt/
    ftp://trumpetti.atm.tut.fi/gcrypt/
    ftp://mirror.cict.fr/gnupg/
    ftp://ftp.strasbourg.linuxfr.org/pub/gnupg/
    ftp://ftp.cert.dfn.de/pub/tools/crypt/gcrypt/
    ftp://ftp.franken.de/pub/crypt/mirror/ftp.gnupg.org/gcrypt/
    ftp://ftp.freenet.de/pub/ftp.gnupg.org/gcrypt/
    ftp://hal.csd.auth.gr/mirrors/gnupg/
    ftp://igloo.linux.gr/pub/crypto/gnupg/
    ftp://ftp.uoi.gr/mirror/gcrypt/
    ftp://ftp.crysys.hu/pub/gnupg/
    ftp://ftp.kfki.hu/pub/packages/security/gnupg/
    ftp://ftp.hi.is/pub/mirrors/gnupg/
    ftp://ftp.heanet.ie/mirrors/ftp.gnupg.org/gcrypt/
    ftp://ftp3.linux.it/pub/mirrors/gnupg/
    ftp://ftp.linux.it/pub/mirrors/gnupg/
    ftp://ftp.bit.nl/mirror/gnupg/
    ftp://ftp.demon.nl/pub/mirrors/gnupg/
    ftp://ftp.surfnet.nl/pub/security/gnupg/
    ftp://sunsite.icm.edu.pl/pub/security/gnupg/
    ftp://ftp.iasi.roedu.net/pub/mirrors/ftp.gnupg.org/
    http://ftp.gnupg.tsuren.net/
    http://www.mirror386.com/gnupg/
    ftp://ftp.sunet.se/pub/security/gnupg/
    ftp://mirror.switch.ch/mirror/gnupg/
    ftp://ftp.mirrorservice.org/sites/ftp.gnupg.org/gcrypt

    http://gnupg.unixmexico.org/ftp/
    ftp://ftp.gnupg.ca/
    http://gulus.usherbrooke.ca/pub/appl/GnuPG/
    http://mirrors.rootmode.com/ftp.gnupg.org/

    ftp://ftp.planetmirror.com/pub/gnupg/

    ftp://pgp.iijlab.net/pub/pgp/gnupg/
    ftp://ftp.ring.gr.jp/pub/net/gnupg/
    ftp://gnupg.cdpa.nsysu.edu.tw/gnupg/
  ];

  # kernel.org's /pub (/pub/{linux,software}) tree.
  kernel = [
    http://www.all.kernel.org/pub/
    http://ramses.wh2.tu-dresden.de/pub/mirrors/kernel.org/
    http://linux-kernel.uio.no/pub/
    http://kernel.osuosl.org/pub/
    ftp://ftp.funet.fi/pub/mirrors/ftp.kernel.org/pub/
  ];

  # Mirrors of ftp://ftp.kde.org/pub/kde/.
  kde = [
    "http://download.kde.org/download.php?url="
    http://ftp.gwdg.de/pub/x11/kde/
    ftp://ftp.heanet.ie/mirrors/ftp.kde.org/
    ftp://ftp.kde.org/pub/kde/
    ftp://ftp.funet.fi/pub/mirrors/ftp.kde.org/pub/kde/
  ];

  # Gentoo files.
  gentoo = [
    http://ftp.snt.utwente.nl/pub/os/linux/gentoo/
    http://distfiles.gentoo.org/
    ftp://mirrors.kernel.org/gentoo/
  ];

  savannah = [
    ftp://mirror.csclub.uwaterloo.ca/nongnu/
    ftp://mirror.publicns.net/pub/nongnu/
    ftp://savannah.c3sl.ufpr.br/
    http://download.savannah.gnu.org/
    http://ftp.cc.uoc.gr/mirrors/nongnu.org/
    http://ftp.twaren.net/Unix/NonGNU/
    http://mirror.csclub.uwaterloo.ca/nongnu/
    http://nongnu.askapache.com/
    http://savannah.c3sl.ufpr.br/
    http://www.centervenus.com/mirrors/nongnu/
  ];

  # BitlBee mirrors, see http://www.bitlbee.org/main.php/mirrors.html .
  bitlbee = [
    http://get.bitlbee.org/
    http://get.bitlbee.be/
    http://get.us.bitlbee.org/
    http://ftp.snt.utwente.nl/pub/software/bitlbee/
    http://bitlbee.intergenia.de/
  ];

  # ImageMagick mirrors, see http://www.imagemagick.org/script/download.php.
  imagemagick = [
    http://ftp.nluug.nl/pub/ImageMagick/
    ftp://ftp.sunet.se/pub/multimedia/graphics/ImageMagick/
    ftp://ftp.imagemagick.org/pub/ImageMagick/
    ftp://ftp.imagemagick.net/pub/ImageMagick/
  ];

  # CPAN mirrors.
  cpan = [
    http://ftp.gwdg.de/pub/languages/perl/CPAN/
    ftp://download.xs4all.nl/pub/mirror/CPAN/
    ftp://ftp.nl.uu.net/pub/CPAN/
    http://ftp.funet.fi/pub/CPAN/
    http://cpan.perl.org/
    http://backpan.perl.org/  # for old releases
  ];

  # Debian.
  debian = [
    ftp://ftp.au.debian.org/debian/
    ftp://ftp.de.debian.org/debian/
    ftp://ftp.es.debian.org/debian/
    ftp://ftp.fr.debian.org/debian/
    ftp://ftp.it.debian.org/debian/
    ftp://ftp.nl.debian.org/debian/
    ftp://ftp.ru.debian.org/debian/
    ftp://ftp.debian.org/debian/
    http://archive.debian.org/debian-archive/debian/
    ftp://ftp.funet.fi/pub/mirrors/ftp.debian.org/debian/
  ];

  # Ubuntu.
  ubuntu = [
    http://nl.archive.ubuntu.com/ubuntu/
    http://de.archive.ubuntu.com/ubuntu/
    http://archive.ubuntu.com/ubuntu/
    http://old-releases.ubuntu.com/ubuntu/
  ];

  # Fedora (please only add full mirrors that carry old Fedora distributions as well).
  fedora = [
    http://ftp.nluug.nl/pub/os/Linux/distr/fedora/
    http://ftp.funet.fi/pub/mirrors/ftp.redhat.com/pub/fedora/
    http://download.fedora.redhat.com/pub/fedora/
    http://archives.fedoraproject.org/pub/archive/fedora/
  ];

  # Old SUSE distributions.  Unfortunately there is no master site,
  # since SUSE actually delete their old distributions (see
  # ftp://ftp.suse.com/pub/suse/discontinued/deleted-20070817/README.txt).
  oldsuse = [
    ftp://ftp.gmd.de/ftp.suse.com-discontinued/
  ];

  # openSUSE.
  opensuse = [
    http://opensuse.hro.nl/opensuse/distribution/
    http://ftp.funet.fi/pub/linux/mirrors/opensuse/distribution/
    http://ftp.belnet.be/mirror/ftp.opensuse.org/distribution/
    http://ftp.uni-kassel.de/opensuse/distribution/
    http://ftp.opensuse.org/pub/opensuse/distribution/
    http://ftp5.gwdg.de/pub/opensuse/discontinued/distribution/
    http://ftp.hosteurope.de/mirror/ftp.opensuse.org/discontinued/
    http://opensuse.mirror.server4you.net/distribution/
    http://ftp.nsysu.edu.tw/Linux/OpenSuSE/distribution/
  ];

  # Gnome (see http://ftp.gnome.org/pub/GNOME/MIRRORS).
  gnome = [
    # This one redirects to some mirror closeby, so it should be all you need.
    http://download.gnome.org/

    http://ftp.unina.it/pub/linux/GNOME/
    http://fr2.rpmfind.net/linux/gnome.org/
    ftp://ftp.dit.upm.es/pub/GNOME/
    ftp://ftp.no.gnome.org/pub/GNOME/
    http://ftp.acc.umu.se/pub/GNOME/
    http://ftp.belnet.be/mirror/ftp.gnome.org/
    http://ftp.df.lth.se/pub/gnome/
    http://linorg.usp.br/gnome/
    http://mirror.aarnet.edu.au/pub/GNOME/
    ftp://ftp.cse.buffalo.edu/pub/Gnome/
    ftp://ftp.nara.wide.ad.jp/pub/X11/GNOME/
  ];

  xfce = [
    http://archive.xfce.org/
    http://mirror.netcologne.de/xfce/
    http://archive.se.xfce.org/xfce/
    http://archive.be.xfce.org/xfce/
    http://mirror.perldude.de/archive.xfce.org/
    http://archive.be2.xfce.org/
    http://ftp.udc.es/xfce/
    http://archive.al-us.xfce.org/
    http://mirror.yongbok.net/X11/xfce-mirror/
    http://mirrors.tummy.com/pub/archive.xfce.org/
    http://xfce.mirror.uber.com.au/
  ];

  # X.org.
  xorg = [
    http://xorg.freedesktop.org/releases/
    http://ftp.gwdg.de/pub/x11/x.org/pub/
    http://ftp.x.org/pub/ # often incomplete (e.g. files missing from X.org 7.4)
  ];

  # Apache mirrors (see http://www.apache.org/mirrors/).
  apache = [
    http://apache.cs.uu.nl/dist/
    http://www.eu.apache.org/dist/
    ftp://ftp.inria.fr/pub/Apache/
    http://apache.cict.fr/
    ftp://ftp.fu-berlin.de/unix/www/apache/
    ftp://crysys.hit.bme.hu/pub/apache/dist/
    http://mirror.cc.columbia.edu/pub/software/apache/
    http://www.apache.org/dist/
    http://archive.apache.org/dist/ # fallback for old releases
    ftp://ftp.funet.fi/pub/mirrors/apache.org/
  ];

  postgresql = [
    ftp://ftp.postgresql.org/pub/
    ftp://ftp-archives.postgresql.org/pub/
  ];

  metalab = [
    ftp://mirrors.kernel.org/metalab/
    ftp://ftp.gwdg.de/pub/linux/metalab/
    ftp://ftp.xemacs.org/sites/metalab.unc.edu/
  ];

  # CRAN mirrors (from http://cran.r-project.org/mirrors.html)
  cran = [
    http://cran.r-project.org/
    http://cran.rstudio.com/
    http://mirror.fcaglp.unlp.edu.ar/CRAN/
    http://r.mirror.mendoza-conicet.gob.ar/
    http://cran.csiro.au/
    http://cran.ms.unimelb.edu.au/
    http://cran.at.r-project.org/
    http://www.freestatistics.org/cran/
    http://cran-r.c3sl.ufpr.br/
    http://cran.fiocruz.br/
    http://www.vps.fmvz.usp.br/CRAN/
    http://brieger.esalq.usp.br/CRAN/
    http://cran.stat.sfu.ca/
    http://mirror.its.dal.ca/cran/
    http://probability.ca/cran/
    http://cran.skazkaforyou.com/
    http://cran.parentingamerica.com/
    http://dirichlet.mat.puc.cl/
    http://ftp.ctex.org/mirrors/CRAN/
    http://mirror.bjtu.edu.cn/cran
    http://cran.dataguru.cn/
    http://mirrors.ustc.edu.cn/CRAN/
    http://mirrors.xmu.edu.cn/CRAN/
    http://www.laqee.unal.edu.co/CRAN/
    http://www.icesi.edu.co/CRAN/
    http://mirrors.dotsrc.org/cran/
    http://cran.espol.edu.ec/
    http://cran.univ-lyon1.fr/
    http://mirror.ibcp.fr/pub/CRAN/
    http://ftp.igh.cnrs.fr/pub/CRAN/
    http://cran.irsn.fr/
    http://cran.univ-paris1.fr/
    http://mirrors.softliste.de/cran/
    http://cran.r-mirror.de/
    http://ftp5.gwdg.de/pub/misc/cran/
    http://cran.cc.uoc.gr/
    http://cran.rapporter.net/
    http://ftp.iitm.ac.in/cran/
    http://cran.repo.bppt.go.id/
    http://cran.um.ac.ir/
    http://ftp.heanet.ie/mirrors/cran.r-project.org/
    http://cran.mirror.garr.it/mirrors/CRAN/
    http://cran.stat.unipd.it/
    http://dssm.unipa.it/CRAN/
    http://essrc.hyogo-u.ac.jp/cran/
    http://cran.md.tsukuba.ac.jp/
    http://cran.ism.ac.jp/
    http://cran.nexr.com/
    http://biostat.cau.ac.kr/CRAN/
    http://cran.itam.mx/
    http://www.est.colpos.mx/R-mirror/
    http://cran.xl-mirror.nl/
    http://cran-mirror.cs.uu.nl/
    http://cran.stat.auckland.ac.nz/
    http://cran.uib.no/
    http://cran.stat.upd.edu.ph/
    http://r.meteo.uni.wroc.pl/
    http://cran.dcc.fc.up.pt/
    http://cran.gis-lab.info/
    http://cran.stat.nus.edu.sg/
    http://cran.fyxm.net/
    http://r.adu.org.za/
    http://cran.mirror.ac.za/
    http://cran.es.r-project.org/
    http://ftp.sunet.se/pub/lang/CRAN/
    http://stat.ethz.ch/CRAN/
    http://cran.cs.pu.edu.tw/
    http://cran.csie.ntu.edu.tw/
    http://mirrors.psu.ac.th/pub/cran/
    http://cran.pau.edu.tr/
    http://www.stats.bris.ac.uk/R/
    http://cran.ma.imperial.ac.uk/
    http://star-www.st-andrews.ac.uk/cran/
    http://cran.cnr.berkeley.edu/
    http://cran.stat.ucla.edu/
    http://streaming.stat.iastate.edu/CRAN/
    http://ftp.ussg.iu.edu/CRAN/
    http://rweb.quant.ku.edu/cran/
    http://watson.nci.nih.gov/cran_mirror/
    http://cran.mtu.edu/
    http://cran.wustl.edu/
    http://cran.case.edu/
    http://ftp.osuosl.org/pub/cran/
    http://lib.stat.cmu.edu/R/CRAN/
    http://cran.mirrors.hoobly.com/
    http://mirrors.nics.utk.edu/cran/
    http://cran.revolutionanalytics.com/
    http://cran.fhcrc.org/
    http://cran.cs.wwu.edu/
    http://camoruco.ing.uc.edu.ve/cran/
    http://cran.vinastat.com/
    http://lib.stat.cmu.edu/
  ];

}