Internet is like a Candy Store, Open Source is its Candy

The internet is like a candy store and the candy is free. They're many free stuff online but what makes me excited is the open source, this is high quality free. It may be hard for someone who doesn't program to understand what I'm talking about. I feel spoiled when I run across an open source software. Seriously, these are unequivocally amazing. From programing languages such as PHP, Python and javascript, to libraries like jQuery and jqPlot to applications such as piwik, to software like blender, to frameworks like CodeIgniter, to operating systems like Ubuntu linux, mail transfer agent like Postfix and the list goes on. There's so many its hard to use them all. Here is a list of high quality open source projects per category.