Visual debugging for LuaTeX
The LuaTeX package
lua-visual-debug shows boxes, glues, kerns and penalties in the PDF output.
Requirements: The package has only been tested with LuaTeX and the formats plain and LaTeX. Other formats might work as well, but other engines only show a warning message.
Copyright 2012–2019 Patrick Gundlach (email@example.com) and others (see Git information)
Package version: see Makefile
Public repository: https://github.com/pgundlach/lvdebug
Licensed under the MIT license. See the Lua file for details.
The idea is heavily inspired by Hans Hagen's http://pragma-ade.com/articles/art-visi.pdf