Pure-Data & GEM
Pure-Data is a graphical data-flow programming environment similar to Max/MSP. To find out more about Pure-Data visit the [community page]
Operations in Pure-Data are objects. Objects are selected by typing there name in a box. This is a lot like calling a function or instanciating a class. Where Pure-Data differs is that you relate these operations by drawing connections between them. Here is a really simple example: