Simple HTML Renderer (SHR)
shr.el is an HTML renderer in Emacs as of version 24.4 (based on libxml2, it was originally a part of Gnus). It’s the basis of the web browser eww.
There is some code to render HTML available at Lisp:htmlr.el in case you want to look at an alternative. It is used by the EmacsWebBrowser (EWB).