One thing well. rbenv is concerned solely with switching Ruby versions. It's simple and predictable.

It doesn't use a database (unlike Keepass) and thus doesn't open all passwords at once. Just one at a time. Since it's just a directory of encrypted files, you can access your passwords with any PGP-compatible tool.

Using find and cpio is a more unix-y approach in that you let find do the file selection with all the power that it has, and let cpio do the archiving. It is worth learning this simple use of cpio, as you find it easy to solve problems you bang your ahead against when trying tar.

As Onivim 2 completely handles the rendering layer, this Vim-modelled-as-a-pure-function could focus on just buffer manipulation.

It is responsible for

do something specific and do it well

Epiphany aims to present the simplest interface possible for a browser. Simple does not necessarily mean less-powerful. The commonly-used browsers of today are too big, buggy, and bloated. Epiphany is a small browser designed for the web: not for mail, newsgroups, file management, instant messaging, or coffeemaking. The UNIX philosophy is to design small tools that do one thing and do it well.