Comment by saagarjha

I don't think this is a very popular opinion, but for those shipping software, consider having at least one programmatic way to "monkey patch" it. These are things like a plugin API, dynamically linking it, or using a language with an exposed runtime–things that allow programmatic injection of code, so that users who really care about tweaking the tool can do so. It doesn't even take much effort, either: my text editor has no plugin interface, but one of the reasons I stick with it is because I can hook its calls to libc to customize some of the things I don't like. My preferred mail client happens to lack a certain entitlement that most people don't even know about and that enables an entire cottage industry of software for it. Browsers let you specify some JavaScript to run on each page and suddenly the balance of power on the web tilts significantly towards the user. Even (or especially) if your tool is open source, consider supporting such an interface: it's much nicer to add on to piece of software than fork it.