anchor.diff:  
   MAINTAINER Beaker Feedback <beaker-feedback@twosigma.com>
   
  -RUN apt-get update
  -RUN apt-get dist-upgrade -y
  +RUN apt-get update && apt-get dist-upgrade -y
   
   RUN apt-get install -y software-properties-common python-software-properties
   
  -RUN add-apt-repository -y ppa:webupd8team/java
  -RUN add-apt-repository -y ppa:chris-lea/zeromq
  -RUN add-apt-repository -y ppa:marutter/rrutter
  -RUN add-apt-repository -y ppa:staticfloat/juliareleases
  -RUN add-apt-repository -y ppa:staticfloat/julia-deps 
  -RUN add-apt-repository -y ppa:chris-lea/node.js
  -RUN add-apt-repository -y ppa:cwchien/gradle
  -RUN add-apt-repository -y ppa:nginx/stable
  +RUN add-apt-repository -y ppa:webupd8team/java && \
  +    add-apt-repository -y ppa:chris-lea/zeromq && \
  +    add-apt-repository -y ppa:marutter/rrutter && \
  +    add-apt-repository -y ppa:staticfloat/juliareleases && \
  +    add-apt-repository -y ppa:staticfloat/julia-deps  && \
  +    add-apt-repository -y ppa:chris-lea/node.js && \
  +    add-apt-repository -y ppa:cwchien/gradle && \
  +    add-apt-repository -y ppa:nginx/stable
   
  -RUN apt-get update
  -
  -RUN apt-get install -y nginx gradle-1.12 python g++ make git
  +RUN apt-get update && apt-get install -y nginx gradle-1.12 python g++ make git
   
   
   ##########
  
positive.code: # need to find them in ~beaker.  Unfortunately we can't run just once
  # here because in addition to those files, they also run some apt-gets
  # which need to go as root.
  RUN su -m beaker -c "julia --eval 'Pkg.add(\"IJulia\")'"
  RUN su -m beaker -c "julia --eval 'Pkg.add(\"Gadfly\")'"
  
  RUN mkdir -p /home/beaker/.beaker/v1/config
  RUN echo '{"pref-format" : "1", "languages" : {"Python3" : {"path": "/root/py3k/bin"}}}' > /home/beaker/.beaker/v1/config/beaker.pref.json
  
  RUN chown -R beaker:beaker /home/beaker
  RUN su -m beaker -c "cd /home/beaker/src  && gradle build"
  EXPOSE 8800
  WORKDIR /home/beaker/src
  CMD su -m beaker -c "export PATH=$PATH:/usr/sbin && /home/beaker/src/core/beaker.command --public-server"
  
negative.code: #  Python  #
  ############
  
  RUN apt-get install -y libzmq3-dbg libzmq3-dev libzmq3 \
                         python-pip python-dev python-yaml \
                         python-matplotlib python-scipy
  
  RUN pip install ipython==2.4.1 jinja2 tornado pyzmq pandas 
  
  #############
  #  Python3  #
  #############
  
  # https://bugs.launchpad.net/ubuntu/+source/python3.4/+bug/1290847
  RUN apt-get install -y python-virtualenv python3-dev && \
      virtualenv /root/py3k -p python3 && \
      /root/py3k/bin/pip install ipython[notebook]==2.4.1
  
  #######
  #  R  #
  #######
  
  RUN apt-get install -y r-base r-base-dev libcurl4-gnutls-dev && \
      Rscript -e "install.packages('Rserve',,'http://cran.us.r-project.org')" && \
      Rscript -e "install.packages('ggplot2',,'http://cran.us.r-project.org')" && \
      Rscript -e "install.packages('devtools',,'http://cran.us.r-project.org')" && \
      Rscript -e "install.packages('RJSONIO',,'http://cran.us.r-project.org')" && \
      Rscript -e "install.packages('RCurl',,'http://cran.us.r-project.org')"
  
  ###########
  #  Julia  #
  ###########
  
  RUN apt-get install -y julia && \
      julia --eval 'Pkg.add("IJulia")' && \
      julia --eval 'Pkg.add("Gadfly")'
  
  ##########
  #  Ruby  #
  ##########
  
  # First install zmq3, as per Python instructions above. Then:
  RUN apt-get install -y ruby1.9.1 ruby1.9.1-dev && \
      gem install iruby
  
  ##########
  #  Node  #
  