Mimulus is a Firefox extension that provides a minimally invasive XHTML editor inside the browser. It lets you change the current tab into a malleable document where you can modify existing data and add new elements, without ever seeing the source. Download and install mimulus.xpi, restart Firefox, and then come back here to learn how to use it.
To start editing, click somewhere on the document to make sure it's selected, and then press Ctrl+I. You should now see a blinking cursor, i.e. the caret, inside the document. If you click around, you'll see that the cursor moves to wherever you click. The status bar at the bottom of Firefox should tell you what's happening with Mimulus, for example "Mimulus is on. Editing: p." if you're currently inside a paragraph.
To enter text, try clicking somewhere in this paragraph and just start typing. You can delete things and use arrow keys too, and paste things in using Ctrl+V (even on OS X). To save the document, press Ctrl+S; Mimulus will confirm in the status bar that the save has succeeded, noting the size of the document too.
To use the <em> element, press Ctrl+E whilst typing and everything you type thereafter will be emphasized like this. Note that again the status bar should tell you which element you're inside, "Editing: em." To exit emphasis mode, press Return. To use the <strong> element, you can use Ctrl+R, which will produce text like this. Again, Return exits.
Links can also be made in the same way, using Ctrl+L, but this time you'll get a Javascript prompt asking for the URI of the link location. You can also turn existing text into emphasis, strong emphasis, and links just by selecting it and then pressing the appropriate key combination.
To remove an inline element, make sure that the cursor is inside the element that you want to turn back into text, and then press Ctrl+Y. For example, that'd turn "this" back into "this".
To make a new paragraph element, <p>, if you're at the end of a current paragraph or other block level element you can press either Return or Ctrl+N. Try it: go to the end of this paragraph, and press Return. It should create a new blank paragraph underneath this one that you can then type into. It will also autosave the current document (see the Bugs! section for why).
All of the following block level elements can be used in the same way as <p>, i.e. by making sure you're at the end of the current block level element and then pressing the appropriate key combination. The only exceptions are that when inside a <pre> element, you can press the combinations at any time, except for Return which won't work anywhere inside a <pre> including at the end since that inserts newlines instead.
Additionally, using Ctrl+T you can toggle between a <p> and a <pre> element. Try it by selecting somewhere in this paragraph and pressing Ctrl+T a few times. Then try it on the following preformatted section:
Note how when switching back and forwards it preserves the formatting, remembering where the line breaks are.
Again, don't forget that you can use Ctrl+N to exit from a <pre> section and create a new paragraph.
If you refresh a page, or navigate away from it, in the middle of a Mimulus sesson, Mimulus will prompt you to make sure that you really want to do that. This is very useful for when some key combination accidentally refreshes the page or goes through the history, making sure that you don't lose your data. If you find it annoying, make sure to always turn Mimulus off again with Ctrl+I once you're finished editing a document. Mimulus will also autosave after every block level element creation, &c.
When editing at the very end of the screen, the cursor will go off of the bottom of the screen and Firefox won't follow it. This is kinda strange since when you use the arrow keys, Firefox does follow it, but there's probably a Javascript fix for it.
The cursor sometimes doesn't display properly in <pre> sections. You can work around this by pressing Ctrl+M whilst inside a <pre> element to turn it into a <textarea>, which you can then edit normally.
The source isn't very pretty yet, and this probably will probably be better solved using an external tidying script rather than by messing around with text justification and so on within Mimulus itself.
Mimulus is good to use as a lightweight XHTML editor, editing lightweight XHTML documents. There's no support for <hr /> or <img /> or anything fancy like that, and there are still a few bugs as mentioned above; but if you're doing fairly heavy editing of a lot of notes, it can be a rather wonderful experience to just edit inside the browser quite transparently.
Another point is that Mimulus should preserve any additions such as stylesheets and images that you add using other editors, so it can be used in conjunction with other editors, or can be used on heavily templated pages. I'm mainly hoping to use it to take quick notes that ought to be formatted in HTML but would be tiresome to type up in emacs even using nxml-mode.
Sometimes you might end up with spurious carets all over the place, which seems to be a bug in Firefox. If you get these anyway, or other redrawing errors, you can try doing Ctrl+S to save the document, then F5 or Command+R to refresh the document.
Sean B. Palmer