Update: I've made this available on github. It's otherwise (so far) unchanged. Feedback welcome!

Here is the home page of this font, and here are Andrew Pitts' pages about Nominal Sets.

--Keith Wansbrough, 2014-05-09.

Just type make install, or do the following (for a local install):

• Make the directory ~/texmf/fonts/source/public/fresh/
• Place all the *.mf files into this directory
• Make the directory ~/texmf/tex/latex/misc/
• Place fresh.sty and ufresh.fd into this directory

\usepackage{fresh}

$\freshquant$  is the fresh quantifier
$\apart$ is the apartness relation
$\fprod$ is the fresh product

That's it! Enjoy.

--Keith Wansbrough, 2001-06-05.