Can I use software written for an release (lets say 0.8.x) of gstreamer, and have it run correctly against a modern release (such as 1.2.x or 1.4.x)? Because t

Can I use software written for an release (lets say 0.8.x) of gstreamer, and have it run correctly against a modern release (such as 1.2.x or 1.4.x)? Because that works with th kernel, as it most certainly does have a stable userspace ABI. Internal stability is not a big concern unless you're trying to hide the source code (proprietary driver). Linus' guarantee about not breaking userspace is very widely known, so I'm sure you know this. The GP was absolutely correct: while you have the luxury of being able to "move fast and break things" as a leaf app that nobody depends on[1], for most everything else "reliability" and "doesn't give me lots of extra work" are far more important than any other feature. This is really just an extension of why it is considered a good idea to write maintainable, modular code instead of leaving people with a mess of spaghetti to debug. [1] That changes if your userspace grows and people ARE depending on it.