Suggestions for scrextend

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

Package scrlttr2: KOMA-Script letter class
Package scrletter: Letter extension to KOMA-Script classes
Package scrlayer-scrpage: Define and manage page styles
Package scrdate: Calendar date operations
Package scrlayer-notecolumn: Control note columns parallel to the main text
Package koma-script-sfs: KOMA-Script letter class option for Finnish
Package koma-script-obsolete: Deprecated packages from KOMA-Script
Package scrlayer: Manage text layers within KOMA-Script
Package scrjura: KOMA-Script support for lawyers, etc.
Package scrartcl: KOMA-Script article class
Package scrreprt: KOMA-Script report class
Package scrbook: KOMA-Script book class
Package scrlfile: Installation control for KOMA-Script packages
Package scrtime: Show the time of a LaTeX run
Package typearea: Set page margins
Package scraddr: Provide data from scrlttr2’s address files
Package scrbase: Provide basic features for KOMA-Script
Package tocbasic: Management of tables/lists of contents (and the like)
Package scrpage2: Control of page headers and footers in LaTeX
Package script: Variant report and book styles
Package koma-script: A bundle of versatile classes and packages
Package stage: A LaTeX class for stage plays
Package screenplay: A class file to typeset screenplays
Package screenwriter: Write film and television screenplays
Package tocstyle: Define style of Table of contents (etc) files
Package fhj-script: Classes and packages for formatting documents for FH JOANNEUM
Package koma-moderncvclassic: Makes the style and command of moderncv (style classic) available for KOMA-classes and thus compatible with BibLaTeX
Package theatre: A sophisticated package for typesetting stage plays
Package dramatist: Typeset dramas, both in verse and in prose
Package drama: Production-style stage script in LaTeX
Package musical: Typeset (musical) theatre scripts