Suggestions for setouterhbox

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

Package centernot: Centred \not command
Package settobox: Assigning dimensions of a box to a length register
Package colonequals: Colon equals symbols
Package chemarr: Arrows for chemists
Package resizegather: Automatically resize overly large equations
Package stackrel: Enhancement to the \stackrel command
Package boxedminipage: Framed minipages of a specified total width (text and frame combined)
Package efbox: Extension of \fbox, with controllable frames and colours
Package collectbox: Collect and process macro arguments as boxes
Package realboxes: Variants of common box-commands that read their content as real box and not as macro argument
Package upgreek: Upright Greek letters
Package tcolorbox: Coloured boxes, for LaTeX examples and theorems, etc.
Package hypgotoe: Links to embedded files
Package pbox: A variable-width \parbox command
Package makebox: Defines a \makebox* command
Package fitbox: Fit graphics on a page
Package eolgrab: Catch arguments delimited by end of line
Package flags: Setting and clearing of flags in bit fields
Package enparen: Consistent nested brackets
Package bmpsize: Extract size and resolution data from bitmap files
Package hyphsubst: Substitute hyphenation patterns
Package engord: Converts numbers to English ordinal numbers
Package hypbmsec: Hypertext bookmarks in sectioning commands
Package fibnum: Generate Fibonacci numbers
Package iflang: Expandable checks for the current language
Package rotchiffre: Perform simple rotation cyphers
Package stampinclude: Inclusion based on .aux file date stamps
Package thepdfnumber: Print PDF numbers with minimal digits
Package twoopt: Definitions with two optional arguments
Package ifdraft: Detect draft and final class options
Package pdfcolparcolumns: Fix colour problems in package parcolumns