anchor.diff:  rec {
   
  -  # Content-addressable Nix mirrors.
  +  # Content-addressable Nix mirrors
     hashedMirrors = [
       http://tarballs.nixos.org
     ];
  
positive.code:     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://cran.usthb.dz/
      http://mirror.fcaglp.unlp.edu.ar/CRAN/
      http://cran.csiro.au/
      http://cran.ms.unimelb.edu.au/
      http://cran.at.r-project.org/
      http://www.freestatistics.org/cran/
      http://nbcgib.uesc.br/mirrors/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://cran.utstat.utoronto.ca/
      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://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.nic.cz/R/
      http://mirrors.dotsrc.org/cran/
      http://cran.espol.edu.ec/
      http://cran.salud.gob.sv/
      http://ftp.eenet.ee/pub/cran/
      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://cran.cardse.net/
      http://mirrors.softliste.de/cran/
      http://ftp5.gwdg.de/pub/misc/cran/
      http://cran.sciserv.eu/
      http://cran.uni-muenster.de/
      http://cran.cc.uoc.gr/mirrors/CRAN/
      http://cran.rapporter.net/
      http://cran.hafro.is/
      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://cran.ism.ac.jp/
      http://cran.md.tsukuba.ac.jp/
      http://cran.nexr.com/
      http://healthstat.snu.ac.kr/CRAN/
      http://cran.biodisk.org/
      http://rmirror.lau.edu.lb/
      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://ftp.cixug.es/CRAN/
      http://cran.es.r-project.org/
      http://ftp.sunet.se/pub/lang/CRAN/
      http://stat.ethz.ch/CRAN/
      http://ftp.yzu.edu.tw/CRAN/
      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://mirrors.ebi.ac.uk/CRAN/
      http://cran.ma.imperial.ac.uk/
      http://mirror.mdx.ac.uk/R/
      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/
    ];
  
    # Hackage mirrors
  
negative.code:     http://kent.dl.sourceforge.net/sourceforge/
    ];
  
    # SourceForge.jp
    sourceforgejp = [
      http://osdn.dl.sourceforge.jp/
      http://jaist.dl.sourceforge.jp/
  