I've naively implemented text rendering, selection, etc from scratch in a text editor, and if you only support monospace, it's pretty simple. The hardest part i

I've naively implemented text rendering, selection, etc from scratch in a text editor, and if you only support monospace, it's pretty simple. The hardest part in software is to not implement features. A trick is to only implement the complex features for the users that need it - in another VCS branch. Or you make an abstraction layer. But abstraction layers are hard, and if they are not air tight (non leaky) you are worse off, because then the developer need to know both layers. Then there is the third strategy, which I would call an anti-pattern, that when enough features have built up, in order to get rid of the relics you rewrite it from scratch, preferably in a new framework. I also believe most advancements in science are accidental, like penicillin, and lexically scoped modules - so if we do not do things, like new frameworks, and re-invent the wheel, the CS field wouldn't advance.