Suggestions for getoptk

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

Package defstring: Define macros as verbatim macros
Package styledcmd: Handling multiple versions of user-defined macros
Package ccool: A key-value document command parser
Package ltxnew: A simple means of creating commands
Package xoptarg: Expandable macros that take an optional argument
Package xnewcommand: Define \global and \protected commands with \newcommand
Package optparams: Macros with multiple optional parameters
Package cdcmd: Expandable conditional commands for LaTeX
Package lambdax: Use Lambda expression within LaTeX
Package mathcommand: \newcommand-like commands for defining math macros
Package xfp: Interface to the LaTeX3 floating point unit
Package xparse: A generic document command parser
Package inlinedef: Inline expansions within definitions
Package cssyntax: Readable, self-documenting command names for LaTeX package authors
Package xtemplate: A high-level interface for declaring document commands
Package letltxmacro: Let assignment for LaTeX macros
Package advice: Extend commands and environments
Package default: Provide default parameters for TeX macros
Package eoldef: Define commands which absorb the whole source line as arguments
Package ifis-macros: Check if a given input string is a number or dimension for TeX
Package extradefs: A miscellany of support macros
Package redefine: Conditional macro, etc., definitions
Package unouter: Suppress \outer flags in Plain TeX
Package declare: Local register name declarations
Package namedef: TeX definitions with named parameters
Package plipsum: Lorem ipsum for Plain TeX developers
Package dvisvgm-def: Colour and Graphics support for dvisvgm
Package dvipdfmx-def: Configuration file for dvipdfmx graphics
Package pdftex-def: Colour and Graphics support for pdfTeX
Package graphics-def: Colour and graphics option files
Package serbian-def-cyr: Serbian cyrillic localization