Suggestions for Shadebox

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

Package frame: Framed boxes for Plain TeX
Package swrule: Lines thicker in the middle than at the ends
Package outerhbox: Collect horizontal material for contributing to a paragraph
Package umrand: Package for fancy box frames
Package shade: Add background shading to text regions
Package shadbox: Shade the background of any box
Package roundbox: Round boxes in LaTeX
Package crbox: Boxes with crossed corners
Package ghab: Typeset ghab boxes in LaTeX
Package tram: Typeset tram boxes in LaTeX
Package postit: A LaTeX package for displaying Post-it notes
Package longfbox: Draw framed boxes with standard CSS attributes that can break over multiple pages
Package codebox: Highlighted source code in a fancy box
Package boxit-ltx: An environment for boxing things
Package boxit: Draw a box around a text
Package ovalfbox: Boxes with frames whose corners are rounded
Package split: Box two chunks of text side-by side
Package tabbingbox: Save a tabbing environment in a box
Package coloredtheorem: A colourful boxed theorem environment
Package boites: Boxes that may break across pages
Package mdframed: Framed environments that can split at page boundaries
Package framed: Breakable framed and shaded boxes
Package ruler: A typographic ruler for TeX
Package olsak-misc: Collection of plain TeX macros written by Petr Olšák
Package arabic: Read a lower-case roman number
Package backgrnd: Mark text with grey background or change bar
Package dow: Calculate day of week from a numeric date
Package emtrees: Draw labelled trees, using emTeX \specials
Package fakebold: A simple macro for faking bold fonts
Package hep-gen: Generic macros for quantum physics
Package longdiv: Long division arithmetic problems