Suggestions for plstmary
The following packages have something in common with the package plstmary. The packages are ordered in decreasing similarity.
- yagusylo: A symbol loader
 - casiofont: Support for the Casio ClassWiz font
 - font-change: Macros to change text and mathematics fonts in plain TeX
 - panda: A package to estimate the blackness of fonts
 - mathtime-pln: Plain TeX macros for using MathTime and MathTime Plus
 - musicography: Accessing symbols for music writing with pdfLaTeX
 - ec-plain: Use EC fonts in Plain TeX
 - hmtrump: Describe card games
 - esint: Extended set of integrals for Computer Modern
 - xetexfontinfo: Report font features in XeTeX
 - symbolindex: Generate a list of symbols with different subgroups
 - typicons: Font containing a set of web-related icons
 - fontmfizz: Font Mfizz icons for use in LaTeX
 - academicons: Font containing high quality icons of online academic profiles
 - unimath-plain-xetex: OpenType math support in (plain) XeTeX
 - alchemist: Typeset alchemist and astrological symbols
 - symbats3: Macros to use the Symbats3 dingbats fonts
 - bahaistar: METAFONT source and macros for the Bahá’í nine-pointed star
 - ifis-macros: Check if a given input string is a number or dimension for TeX
 - esvect: Vector arrows
 - cookingsymbols: Symbols for recipes
 - fontch: Changing fonts, sizes and encodings in Plain TeX
 - font-selection: Font selection for plain TeX
 - plain-cm: Variable sized fonts in Plain TeX
 - pdcmac: Damian Cugley's document tools
 - font-change-xetex: Macros to change text and mathematics fonts in plain XeTeX
 - bibplain: Simple macros for using BibTeX with Plain TeX
 - extradefs: A miscellany of support macros
 - redefine: Conditional macro, etc., definitions
 - unouter: Suppress \outer flags in Plain TeX
 - declare: Declare register names locally