Suggestions for tcolorbox
The following packages have something in common with the package tcolorbox. The packages are ordered in decreasing similarity.
- coloredtheorem: A colourful boxed theorem environment
 - listings: Typeset source code listings using LaTeX
 - framedsyntax: Typeset the syntax of commands and environments within coloured boxes
 - boites: Boxes that may break across pages
 - framed: Framed or shaded regions that can break across pages
 - mdframed: Framed environments that can split at page boundaries
 - enverb: Read an environment verbatim
 - sverb: A set of verbatim text manipulations
 - fancyvrb: Sophisticated verbatim text
 - latexdemo: Demonstrate LaTeX code with its resulting output
 - examplep: Verbatim phrases and listings in LaTeX
 - showexpl: Typesetting LaTeX source code
 - adjustbox: Graphics package-alike macros for “general” boxes
 - callouts-box: Provides visually appealing callout boxes
 - termsim: Simulate Win10, Ubuntu, and Mac terminals
 - codebox: Highlighted source code in a fancy box
 - cnltx: LaTeX tools and documenting facilities
 - joinbox: Join boxes vertically or horizontally
 - verbatimbox: Deposit verbatim text in a box
 - verbasef: VERBatim Automatic Splitting of External Files
 - newvbtm: Define your own verbatim-like environment
 - pynotebook: pynotebook presents (raw, Markdown or Python) codes (and execution with LuaLaTeX) as in a Jupyter Notebook
 - creationboites: Macros to create simple tcolorbox with some customizations
 - minted: Highlighted source code for LaTeX
 - ffcode: Fixed-font code blocks formatted nicely
 - minted-code: Predefined environments for typesetting LaTeX code with minted
 - tkzexample: Package for the documentation of all tkz-* packages
 - ydoc: Macros for documentation of LaTeX classes and packages
 - tkz-doc: Documentation macros for the TKZ series of packages
 - cprotectinside: Use cprotect arbitrarily nested
 - saveenv: Save environment content verbatim