I was struck by the statement "the version control system is a first order effect on software, along with two others - the build system and the bugtracker. Those choices impact absolutely everything else. Things like IDEs, by comparison, don't matter at all," in a post by Bill de hÓra. It's not 100% true -- innovations like integrated debugging (Turbo Pascal?), refactoring (IDEA), and the Smalltalk browser -- can be enormous, but there is certainly more than a grain of truth to it.