Suggestions for schemata

The following packages have something in common with the package schemata. The packages are ordered in decreasing similarity.

Package youngtab: Typeset Young-Tableaux
Package chemfig: Draw molecules with easy syntax
Package luatexja: Typeset Japanese with Lua(La)TeX
Package ltxcmds: Some LaTeX kernel commands for general use
Package namedef: TeX definitions with named parameters
Package pdftexcmds: LuaTeX support for pdfTeX utility functions
Package hologo: A collection of logos with bookmark support
Package iftex: Am I running under pdfTeX, XeTeX or LuaTeX?
Package luakeys: A Lua module for parsing key-value options
Package tuple: Expandable operations for tuples of numbers
Package lparse: Parse macro arguments with Lua using xparse-like specification
Package expkv-bundle: An expandable key=val implementation and friends
Package polexpr: A parser for polynomial expressions
Package witharrows: Aligned math environments with arrows for comments
Package opbible: Creating a study Bible with OpTeX
Package collargs: Collect arguments of any command
Package localloc: Macros for localizing TeX register allocations
Package tokmap: Iterate over a token list expandably, without dropping spaces or braced groups
Package plainpkg: A minimal method for making generic packages
Package etoolbox-generic: A loader for etoolbox.sty in non-LaTeX formats
Package addtoluatexpath: Add paths to Lua packages and input TeX files
Package calcfrac: Calculates the value of an expression containing fractions
Package fltpoint: Simple floating point arithmetic
Package langcode: Simple language-dependent settings based on language codes
Package advice: Extend commands and environments
Package mathdots: Commands to produce dots in math that respect font size
Package multido: A loop facility for Generic TeX
Package multiexpand: Variations on the primitive command \expandafter
Package gobble: More gobble macros for PlainTeX and LaTeX
Package duckuments: Create duckified dummy content
Package kantlipsum: Generate sentences in Kant’s style