https://refactoring.guru/fr/refactoring/techniques
https://microsoft.github.io/monaco-editor/
https://getrector.org/
https://codesandbox.io/
https://carbon.now.sh/
http://racksburg.com/choosing-an-http-status-code/
http://www.pythonapi.com/
http://codeshare.io/
https://cssanimation.rocks/
https://codeclimate.com/
http://ideone.com/
http://sahandsaba.com/thirty-python-language-features-and-tricks-you-may-not-know.html
http://www.codewars.com/
http://runnable.com/
http://ace.c9.io/#nav=about
http://css-tricks.com/snippets/css/make-pre-text-wrap/
http://codepen.io/
http://rips-scanner.sourceforge.net/
https://pypi.python.org/pypi/flake8
https://github.com/phurix/pagerank/
http://www.maxmind.com/app/postalcode
http://code.google.com/more/table/
http://codepad.org/
http://blogs.sitepoint.com/2008/11/04/7-places-to-find-the-code-you-need/
http://jsfiddle.net/
http://www.coderun.com/
http://marijn.haverbeke.nl/codemirror/
http://code.google.com/apis/ajax/playground/