Suggestions for Boxhandler

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

Package everysel: Provides hooks into \selectfont
Package bophook: Provides an At-Begin-Page hook
Package thrmappendix: Theorems, lemmas, etc., in appendix
Package atveryend: Hooks at the very end of a document
Package auxhook: Hooks for auxiliary files
Package atbegshi: Execute stuff at \shipout time
Package everypage: Provide hooks to be run on every page of a document
Package eso-pic: Add picture commands (or backgrounds) to every page
Package everyshi: Take action at every \shipout
Package atenddvi: Provides the \AtEndDvi command
Package caption: Customising captions in floating environments
Package fltpage: Place caption on an adjacent page
Package zaccone: Different configuration for different captions
Package multicap: Format captions inside multicols
Package hep-float: Convenience package for float placement
Package caption2: Superseded version of the caption package
Package bicaption: Support for bilingual captions
Package ltcaption: Fix some caption problems in longtables
Package subcaption: Support for sub-captions
Package ftcap: Allows \caption at the beginning of a table-environment
Package captcont: Retain float number across several floats
Package subfigure: Deprecated: Figures divided into subfigures
Package floatbytocbasic: An enhancement to package float using package tocbasic
Package floatrowbytocbasic: An enhancement to package floatrow using package tocbasic
Package phffullpagefigure: Figures which fill up a whole page
Package topfloat: Move floats to the top of the page
Package photo: A float environment for photographs
Package float: Improved interface for floating objects
Package dblfloatfix: Fixes for twocolumn floats
Package endfloat: Move floats to the end, leaving markers where they belong
Package easyfloats: An easier interface to insert figures, tables and other objects in LaTeX