I just upgraded to Eclipse Kepler, the non-J2EE version. The HTML Editor is missing. I read elsewhere that I could install the "Web Page Editor", which I did, but the system now generates all kinds of errors when building my project. Apparently it can't find some JSF classes. I have no interest in using JSF.
The Web Page Editor install did include the HTML Editor, but it was so much trouble I had to uninstall. How do I get my old HTML Editor back?
Alternatively, you can just install the "HTML Editor" from the WST package (the same one provided in Java EE Edition) in Eclipse 4.x, just by looking for "HTML Editor" in the marketplace (but, indeed, i haven't been able to found it in the "install new software").
On my side i prefer to work on Eclipse "Java Edition" most of the time (just adding the few additionnal features i really need).
Go to Install New Softwares-> Select your version eclipse repo. eg Mars - http://download.eclipse.org/releases/mars -> Expand Web,XML, JAVA EE option -> Install Eclipse Web Developer Tools
I have used CodeMix for a while and it's a wonderful tool, it can easily install as a plugin and a wide tools will be available like HTML Validation, Emmet, CSS IntelliSense, Snippets, take a look in this site https://www.genuitec.com/sox/tech/html5-with-codemix/
I had a similar issue once, and I tried a HTML editor addon for eclipse, but haven't found one that's any better than the one that comes with the Java EE edition of eclipse.
I suggest you download the Eclipse IDE for Java EE Developers.
You may want to install Eclipse Web Developer Tools 
Bet you after edit HTML you will have to edit CSS and JavaScrip too
