Suggestions for placeins-plain

The following packages have something in common with the package placeins-plain. The packages are ordered in decreasing similarity.

Package newinsert: Reworking Plain TeX’s insert macros
Package figplace: Floating figures in Plain TeX
Package border: Draw a black border around a Plain TeX page
Package cropmrks: Add crop marks to a Plain TeX document
Package varindent: Make paragraph indentation match the length of the line above
Package plain-widow: Three output routines that extend \plainoutput
Package placeins: Control float placement
Package firstline: Print the first line of a paragraph in a different font
Package automagic: Automatic counter numbering in Plain TeX
Package side: Rotated floats for LaTeX 2.09
Package portland: Simple portrait/landscape switching
Package landscape: Set up for typesetting in landscape
Package pos-at: Position things at absolute positions on the page
Package raggedr: Set an entire document raggedright
Package sober: Makes appearance of standard styles more sober
Package hep-float: Convenience package for float placement
Package letter-plain: Letter macros for Plain TeX
Package lettermac: Simple macros for writing letters (Plain TeX)
Package label-pln: Print address labels in three columns
Package plain-cm: Variable sized fonts in Plain TeX
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 pi: Calculate pi
Package settosize: Scale text to given width
Package labelmac3: Print Avery 5160 labels for laser printers
Package autotoc: Table of contents in Plain TeX
Package boxit: Draw a box around a text
Package bellmac: Outline scheme for form letter production
Package bfsymb: Generate bold symbols in Plain TeX mathematics