TeX4ht is a highly configurable TeX-based authoring system dedicated mainly to produce hypertext. It interacts with TeX-based applications through style files and post processors, leaving the processing of the source files to the native TeX compiler. Consequently, TeX4ht can handle the features of TeX-based systems in general, and of the LaTeX and AMS style files in particular. This is a command line utility.
System is executed with various scripts, most basic one is htlatex for HTML and XHTML conversion. More advanced is make4ht, which supports execution of supporting commands such as bibtex or makeindex and postprocessing of output files, using simple build files. tex4ebook is based on make4ht and can be used for direct conversion to EPub, EPub 3 and Mobi.