Linux, which is a free and open computer operating system can be used instead of more popular options like Apple and Microsoft Windows. We already know that Windows is a big polluter, and Apple has been criticized creatively for their lack of green policies. The alternative to these polluters is linux (my favourite linux version is Ubuntu).
To make computing even easier, a blogger has put up a list of software that is commonly pirated with a list of free and open alternatives. For example, no need to buy Microsoft Office when you can use Open Office.