Another example that I worked on last week is for the UI framework Kivy. Most of the core libraries are in Cython, and particularly for the graphics stuff I thi

Another example that I worked on last week is for the UI framework Kivy. Most of the core libraries are in Cython, and particularly for the graphics stuff I think it's a nice balance of execution speed and ease of development. In particular, it's trivial to use the Cython objects from pure Python, without having to mess with the CPython API on either side. Here's an example of the experimental SVG parser/renderer we've been working on over the past few weeks, if you want to see some more "real world" Cython: https://github.com/kivy/kivy/blob/master/kivy/graphics/svg.pyx https://github.com/kivy/kivy/blob/master/kivy/graphics/svg.p...