histyle – A "HighStyle" environment for TeX
Described as “very rudimentary beginnings of HighStyle environment for [Plain] TeX”. The package defines a bunch of macros and (LaTeX-like) environments in support of its aim.
(There's no documentation, to speak of, and no information about HighStyle, on which the package is supposedly based: there seems to be no information about HighStyle on the Web, either.)
Download the contents of this package in one zip archive (6.2k).