This year, researcher David Buchanan tried to implement parallel decoding using the iDOT information. During development, he made a simple programming mistake and ended up making a wonderful discovery. He could create a PNG file with platform-dependent rendering. It looked one way on Windows, Linux, Firefox, and Chrome, and a different way on a Mac with default Apple applications, like the Safari web browser. (He found that Apple had implemented the same bug!) Buchanan provided two sample pictures (Hello World and computers) to demonstrate this per-platform rendering. It didn't take long for other people to use his code and generate other examples. Many of these images were uploaded to FotoForensics:

Pytest is a very complete test framework for Python. I like how you can write a basic unittest.TestCase and the py.test test runner command will inject all its magic at runtime, without you having to directly import anything: awesome separation of concerns.

This modularity comes at a cost …