Suggestions for PostIt

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

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 codebox: Highlighted source code in a fancy box
Package longfbox: Draw framed boxes with standard CSS attributes that can break over multiple pages
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 frame: Framed boxes for Plain TeX
Package shadebox: Shade boxes using PostScript specials
Package fancytabs: Fancy page border tabs
Package gradientframe: Simple gradient frames around objects
Package sectionbox: Create fancy boxed ((sub)sub)sections
Package notes: Mark sections of a document
Package alertmessage: Alert messages for LaTeX
Package lroundrect: LaTeX macros for utilizing the roundrect METAPOST routines
Package nccboxes: Elaborate box commands
Package dpcircling: Decorated text boxes using TikZ
Package callout-itembox: A LaTeX package for colored callout item/numbered text boxes with a tinted
Package gitstatus: Include Git information in the document as watermark or via variables
Package highlightx: Highlight formulas or paragraphs
Package proofread: Commands for inserting annotations
Package parselines: Apply a macro to each line of an environment
Package terminalcode: Terminal-style code display with ANSI colors, UTF-8 box-drawing, and dark/light themes
Package ullrcorners: Draw corners on the upper left and lower right sides of a word
Package styleitems: Independent auto-numbered list labels drawn with TikZ
Package parboxx: Two extra alignment options for \parbox
Package callouts-box: Provides visually appealing callout boxes