Punct is heavily indebted to Pollen. Much of its design and code comes from Pollen. And because Punct sources provide bindings for doc and metas just like Pollen markup sources do, you should be able to use Punct sources in Pollen projects without too much trouble.
But there are some big differences, listed below, and they are just that —
Punct provides no project web server for previewing your HTML output. (You can use Pollen’s, or use raco static-web.)
Punct provides no command-line tools for rendering output, and no templating tools. (You can write Racket scripts for these things pretty easily. For templates in particular, consider Adding @-expressions to a Language.)
Punct does not provide a “preprocessor” dialect.
Punct does not offer any tools for ordering content, or for navigation. (But of course, you can still use Pollen’s pagetrees or some scheme of your own.)
Punct generally eschews contracts and makes almost no effort to provide friendly error messages.
Punct does not search through your filesystem for a "pollen.rkt" or other special file to auto-require into your source files. This means there is also no “setup module” mechanism for customizing Punct’s behavior.
Where Pollen’s documentation is generous and patient and does not assume any familiarity with Racket, Punct’s documentation is clipped, and kind of assumes you know what you’re doing.