docopt : Command-line interface description language
ADR Tools : A command-line tool for working with Architecture Decision Records (ADRs).
Hurl : Hurl is a command line tool that runs HTTP requests defined in a simple plain text format.
It can chain requests, capture values and evaluate queries ...
ApiGen : ApiGen is the tool for creating professional API documentation from PHP source code, similar to discontinued phpDocumentor/phpDoc.
PurgeCSS : PurgeCSS is a tool to remove unused CSS. It can be part of your development workflow.
stackoverflow from the terminal.
how2 finds the simplest way to do something in a unix shell. It's like man, but you can query it in natural language.