anchor.diff: -FROM ubuntu
  +# FROM ubuntu
  +FROM debian:jessie
   
  -# install common utils
  -RUN apt-get update -y; \
  -    apt-get install -y apt-utils \
  +# 1. install common utils
  +RUN apt-get update -y \
  +    && apt-get install -y apt-utils \
                          sudo \
                          tmux \
                          nano \
  
positive.code:                        curl \
                         wget \
                         less \
                         software-properties-common; \
      apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
  
  # install build essential for c and cpp
  RUN apt-get update -y; \
      apt-get install -y build-essential; \
      apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
  
  # install python 2 and 3
  RUN apt-get update -y; \
      apt-get install -y python3 \
                         python2.7; \
      apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
  
  # install node.js  
  RUN apt-get update -y; \
      apt-get install -y nodejs; \
      apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
  
  # fix node.js path
  RUN ln -s /usr/bin/nodejs /usr/bin/node
  
  # install npm
  RUN apt-get update -y; \
      apt-get install -y npm; \
      apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
                        
  # install java
  RUN add-apt-repository ppa:webupd8team/java; \
      apt-get -y update; \
      mkdir -p /usr/lib/mozilla/plugins; \
      echo debconf shared/accepted-oracle-license-v1-1 select true | debconf-set-selections; \
      echo debconf shared/accepted-oracle-license-v1-1 seen true | debconf-set-selections; \
      apt-get -y install oracle-jdk7-installer; \
      apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
  
  # install php
  RUN apt-key adv --keyserver hkp://keyserver.ubuntu.com --recv-keys E5267A6C; \
      echo 'deb http://ppa.launchpad.net/ondrej/php5/ubuntu trusty main' > /etc/apt/sources.list.d/ondrej-php5-trusty.list; \
      apt-get update -y; \
      apt-get install -y php5; \
      apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
  
  # add golang
  RUN add-apt-repository ppa:ubuntu-lxc/lxd-stable; \
      apt-get -y update; \
      apt-get install -y golang; \
      apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
  
  # add rust lang
  RUN curl -sSf https://static.rust-lang.org/rustup.sh | sh; \
      rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
  
  # add clisp
  RUN apt-get -y update; \
      apt-get install -y clisp; \
      apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
  
  # add lua
  RUN apt-get -y update; \
      apt-get install -y lua5.3*; \
      apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
  
  # add csharp and probably other .net based language
  RUN apt-get -y update; \
      apt-get install -y mono-xbuild mono-mcs mono-devel; \
      apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
  
  # add ruby
  RUN apt-get -y update; \
      apt-get install -y ruby; \
      apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
  
  # add vb
  RUN apt-get -y update; \
      apt-get install -y mono-vbnc; \
      apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
  
  # install brainfuck
  RUN npm install -y -g brainless; \
      npm cache clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
  
  # install coffee script
  RUN npm install -y -g coffee-script; \
      npm cache clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
  
  
negative.code: RUN apt-get purge -y software-properties-common; \
      apt-get autoclean -y
  
  WORKDIR /home/$USER_NAME
  USER $USER_NAME
  
  #setup wine
  RUN winetricks > /dev/null
  
  # clone slave files
  COPY executer.js executer.js
  