Hey, I created Psalm.

Psalm and similar tools perform type-checking static analysis. This tool does not do type-checking.

It does a few things:

- Complexity analysis, with a few other top-level checks (analysis done here: https://github.com/nunomaduro/phpinsights/blob/966fddbacb17e...)

- Composer dependency security checks (if third-party packages have vulnerabilities)

- It wraps PHP CodeSniffer with some additional sniffs

- It wraps PHPCS Fixer with some additional sniffs

The tool doesn't go out of its way to advertise the fact that it wraps two popular existing tools, but that's the author's prerogative.

I use both this and Psalm. I find PHP Insights very helpful in ensuring I’m meeting the standards I’ve set out because — as Matt notes in his comment — it is essentially a nice interface to various existing code quality tools.

Psalm on the other hand helps keep my code bug free through excellent static analysis.

Psalm is essential, insights is beneficial. I eagerly choose to use both, together, but in a world where you can use just one: Psalm.