Additional Notes for Ubuntu Linux

the Ruby Gem Nokogiri requires libxslt and libxml2 install them with:
```
sudo apt-get install libxslt-dev libxml2-dev
```

D3.js build process fails:

  locale: Cannot set LC_ALL to default locale: No such file or directory

Solution:

  $ sudo locale-gen en_US

D3.js build process fails:

  make[1]: /usr/lib/nodejs:/usr/share/javascript/uglify-js/bin/uglifyjs: Command not found

Workaround:

  $ unset NODE_PATH

and try to build the project again.