Well, just when you thought you knew all the Mac writing apps, along comes something new and radically different.

Diamond is that thing. It’s a rich text editor with much the same capabilities as TextEdit, but with oh so much more style.

Diamond is designed to be different. Each document window is as minimal as a document window could possibly be - there’s no visible border, no title bar, no toolbar. Nothing except a box to put text in. Re-sizing is done with a little diamond-shaped widget the hovers unobtrusively below each window. The document’s title and word count also float down there, but they’re optional extras. Your document will scroll, but not the way you expect - by default, things scroll sideways, in page-width columns. I told you it was radical.

In use, there are echoes of other familiar apps, all mixed up and mashed together. It’s a bit like WriteRoom in the sense that it obscures all your other work, the Finder, the desktop, even the Menu Bar and Dock if you wish; it’s a bit like Stickies or TextEdit, in the sense that it offers standard OS X rich text editing and the ability to roll windows up into a one-line-high strip.

This is how Diamond looks in default colors, but with the screen inverted using Control+Option+Command+8. I find it rather soothing.

Just as each TextEdit document can look wildly different, so can each Diamond document. With some patience and a little imagination, you can turn Diamond into an attractive all-text workspace.

There are bugs present, especially in the all-important prefs window. But the application’s author Geoffrey Alexander is upfront about progress; he cheerfully admits that Diamond “isn’t for everybody (it may not be for anybody…)” - but at the same time urges users to make comments and observations on his web forum.

I shall be doing just that very soon, because I like Diamond a lot and want to see it improve. And Geoffrey’s right - this is not going to appeal to everyone. But there will be some who love it, such as writers who want to have their work in one window and their notes, metadata and outline in another window. Such a system is possible with more complex professional tools like Scrivener and Ulysses, but Diamond offers a simple lo-fi alternative.