This is listings with Rust support.

Listings package

Copyright 1996--2004 Carsten Heinz (the package)
Copyright 1996--2007 individual authors (language drivers)
Copyright 2006--2007 Brooks Moses (continued maintenance)
Copyright 2013--2020 Jobst Hoffmann (continued maintenance)

Released under the LaTeX Project Public License 1.3c or later

The `listings' package is a source code printer for LaTeX.
You can typeset stand alone files as well as listings with
an environment similar to `verbatim' as well as you can
print code snippets using a command similar to \verb'.
Many parameters control the output and if your preferred
programming language isn't already supported, you can make
your own definition.