Here you can find various articles about mostly technical topics.
Actually the name entr is an acronym for Event Notify Test Runner and has nothing to do with the word enter, but I always associate entr with it, because it helps me to get rid off of many ALT-TAB and ENTER strokes. There are ready-to-install packages for Debian and Ubuntu. This packages can be installed with apt-get install entr. If you are on MacOS you can install it via Homebrew with brew install entr.