HTML Tidy  5.5.19
The HTACG Tidy HTML Project
LibTidy

LibTidy is the library version of HTML Tidy. In fact, Tidy is LibTidy; the console application is a very simple C application that links against LibTidy. It’s what powers Tidy, mod-tidy, and countless other applications that perform tidying.

Please note that this content is adapted from the original on SourceForge.