GUItenMark

GUItenMark is a program of a type known as a "graphical front-end". It provides a simplified method of accessing the GutenMark command-line program and (20080601 or later) the GutenSplit command-line program.

In other words, the GutenMark and GutenSplit programs still do all of the work of converting your etext to HTML (or LaTeX), but you no longer have to bother about learning how to use them, or to bother dealing with the command-line if it's not your thing.