Suggestions for Laps

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

Package ifis-macros: Check if a given input string is a number or dimension for TeX
Package automagic: Automatic counter numbering in Plain TeX
Package redefine: Conditional macro, etc., definitions
Package unouter: Suppress \outer flags in Plain TeX
Package declare: Local register name declarations
Package balancedquotes: Code balanced quotes according to document language
Package compare: Macro to compare two strings
Package patch: Modify already-loaded packages
Package knst: Multiple-guess tests
Package ofs: Macros for managing large font collections
Package letter-plain: Letter macros for Plain TeX
Package figplace: Floating figures in Plain TeX
Package lettermac: Simple macros for writing letters (Plain TeX)
Package label-pln: Print address labels in three columns
Package twoside: Two-side typesetting in Plain TeX
Package toc-zar: Plain TeX table of contents macros
Package twocolumns: Knuth’s two-column output macros
Package list: Verbatim listing of text files
Package font-change: Macros to change text and mathematics fonts in plain TeX
Package tokcycle: Build tools to process tokens from an input stream
Package defstring: Define macros as verbatim macros
Package unimath-plain-xetex: OpenType math support in (plain) XeTeX
Package arrayjob: Array data structures for (La)TeX
Package arrayjobx: Array data structures for (La)TeX
Package gates: Support for writing modular and customisable code
Package gtl: Manipulating generalized token lists
Package commado: Expandable iteration on comma-separated and filename lists
Package fenixpar: One-shot changes to token registers such as \everypar
Package dowith: Apply a command to a list of items
Package collargs: Collect arguments of any command
Package localloc: Macros for localizing TeX register allocations