Differences between html-mode and html-helper-mode

Insertion philosophy

html-mode frequently prompts the user in the minibuffer for the data to fill in fields like titles or headers. In html-helper-mode, prompting is a user-controlled option.

Modifying regions

In html-helper-mode, every command will instead modify the region if it is called with a prefix argument.

Automatic text insertion

html-helper-mode can automatically insert skeletons for new documents and also maintain timestamps.

Minimal syntax support

html-helper-mode does its best to tell emacs about the syntax of HTML documents.

Indentation

html-helper-mode indents nested lists

Highlighting

HTML cookies are coloured nicely with hilit19.

Keymap

A few obsolete cookies have been removed, a few new cookies have been added, and the keybindings have been completely rearranged to be compliant with emacs standards.

Completion

HTML cookies can be completed in the buffer with M-TAB.

Missing features

Some features of html-mode are not included. These include the ability to quotify old-style HREFs and automatic naming of anchors