Linux and OpenSSL are two great examples of projects that probably should, but doesn't bother, to do much testing at all. Even if they are both steadily getting

Linux and OpenSSL are two great examples of projects that probably should, but doesn't bother, to do much testing at all. Even if they are both steadily getting better at it. They obviously produce useful results and most would love to see more of it, yet it is tacked on afterwards and often by completely different people than the original developers, not as part of the development process. They have a long way to go to have good enough tests that could be relied on for integration purposes. TDD isn't even on the map. And will probably never be.