Using OPML for Thinking, Writing, Publishing

My dear friend and fellow blogger Koan Bremner has taught me yet another cool trick: If you want to publish a complex, evolving, multi-leveled document online, OPML is a good way to go.

What’s OPML? Outline Processor Markup Language is a file format for outlines. Specifically, it’s a way to use XML (extensible markup language) so that you’re not just typing in text, but actually describing how various chunks of text (or data, or links, etc.) relate to each other within a hierarchy.

The end result is an outline that looks rather like a book’s table of contents (TOC). However, imagine that the actual chapters of the book are embedded within the TOC. So if you want to go straight to, say, Chapter 6, you wouldn’t flip ahead to the page number listed in the TOC. Instead, you would just click on the “chapter 6” line in the TOC, and the text of Chapter 6 would open right there within the TOC. Any subheads within that chapter would work the same way – just click on them, and they unfold. Once a heading or subhead (“topic”) is open, just click on it again to fold it back up.

EXAMPLE: Check out this resource Koan has published on Transitioning from Windows to OS X “Tiger” – a worthy topic if there ever was one.

Here’s why Koan’s document, and the OPML approach which underlies it, is so cool…

Working with a list where each item is basically a semi-independent content module offers some benefits over working with a text or word processing file. I think of it as the “Legos approach” to building a document – it’s easier to revise, mix, and match, while keeping the structure connected.

I find this approach makes it easier to think about certain types of content, especially tutorials, backgrounders and presentations. Working in an OPML outliner forces me to keep the structure of content in mind, which means I don’t lose sight of the big picture. In turn, this often helps my thoughts flow more easily. I’m less likely to wander off into tangents, or neglect to make important connections.

Furthermore, OPML is a good choice for complex “living documents” which are constantly evolving. Think FAQ lists and timelines here. It’s pretty easy to add new topics and rearrange the structure when using an OPML editor.

WRITING TIP: If you have trouble organizing your thoughts so you can write them down, try writing your first draft in an outliner tool. Keep it rough and lean. Think in terms of key terms/ideas and bullet points, rather than sentences and narrative. A good outliner tool makes it easy to move items around – which can be surprisingly helpful for getting a strong, clear flow of ideas going.

…As you progress, you can either continue to flesh your document out in the outliner, or export your outline to a word processor or text editor, whichever is most helpful to your writing process. You may even decide that OPML is the best final format for the document!

When you check out Koan’s guide, read her short list of navigation instructions (i.e., what the various arrows in the document mean). Then play with the document. You’ll see that by clicking on the arrows you can selectively explore various levels of detail, starting from a bare outline and progressing into the full text of Koan’s observations and tips, as well as links to relevant web sites.

Koan created this document using the OPML editor built into her weblogging software, Radio Userland. However, if you don’t have Userland, don’t worry. Koan assured me recently: “Anybody can achieve the same kind of results (even if they don’t use Radio UserLand or don’t have activeRenderer installed) by using the free (and fabulous, I might add) OPML Editor you mentioned, together with the free activeRenderer web service.”

Note: See below for a bit more on ActiveRenderer. This tool/service deserves its own explanation, and I don’t have time to do that now, so I’ll do it later in a separate posting, after I’ve had a chance to play with it.

Or try Dave Winer’s outliner. This lean, nifty, and free program lets you build a structured list of items. The resulting OPML file can include more than just text. You can embed links, images, audio, spreadsheets, data, or whatever type of electronic information or content you want.

Of course, an OPML outline file by itself isn’t very pretty, since OPML is meant to be interpreted by machines, rather than read by humans. If you want to format an OPML outline so it looks cleanly formatted when viewed in a web browser, you’ll need to render it to HTML. This part of the process is a little geeky, but not too bad:

  • Koan uses an outline publishing tool for Radio Userland called ActiveRenderer. This allows people to collapse and expand headings in the outline when viewing it through a web browser. There are probably other tools to do this, I just don’t know what they are yet. (Hint to developers: There’s definitely a market for a user-friendly, platform-independent, standalone OPML renderer, I think!)
  • Here’s how I publish a fully expanded outline (all content is visible, people can’t click to collapse or expand selected headings):
    1. I use the “View in Browser” option under the file menu in Dave Winer’s outliner. This opens a new window in my web browser (Safari seems to work best for me) which displays the OPML outline as a web page.
    2. I save that page as an HTML file. (In Safari, I choose “Save as” and the select the “page source” option).
    3. The formatting for that HTML file is pretty bare-bones. If I want to dress it up a bit, I open that file in my HTML editor, or I apply a Cascading StyleSheet (CSS) to it.

GEEKY NOTE: OPML is potentially useful wherever XML is used – and XML is very popular for all sorts of purposes. Currently, OPML is best known as a way to share collections of feeds (RSS or Atom format).

For example, I’ve published my personal list of must-read feeds as an OPML file (right-click or click-and-hold to download that file). If you want to subscribe to all of those feeds into your feed reader at once, simply import my OPML file into your feed reader.

…All the best feed readers allow OPML import and export. If yours doesn’t, switch to one that does. It’s a pretty crucial feature, I think.

SEE OPML IN ACTION: On Nov. 1, Alex Barnett published an excellent “screencast” which demonstrates how OPML works, as well as a list of OPML resources, applications, and examples. See: Using OPML 101 – Screencast. You’ll need a Flash-enabled web browser to watch and listen to his presentation. It’s well worth watching. Check out the comments, too.

MY OPML WISH LIST: Just off the top of my head, here are some things I’d really love to see…

  • Easy OPML rendering to a word processing document. (I use AppleWorks, NeoOfficeJ, and sometimes Open Office, hint hint to developers)
  • News organizations offering a rendered OPML article index, by topic
  • More e-books, reports, and white papers published as rendered OPML documents
  • OPML export to a wiki
  • More blogging tools with built-in OPML renderers. (I used WordPress and Typepad, hint hint to developers)
  • An easy to use, standalone, platform-neutral OPML renderer. (UPDATE NOV. 7: Looks like this wish, at least, may have already come true…)

4 thoughts on Using OPML for Thinking, Writing, Publishing

Comments are closed.

  1. Hi Amy. Great post.

    You’re on a mac, right? I’ve been outlining on the mac for a few years – my tool of choice is OmniOutliner 3 Pro ( It’s a richer outliner from a gui perspective than the outliner, and can import/export opml. It also does a rather nifty job of exporting to Word. What OmniOutiner sorely lacks is any type of collaborative component, such as outline sharing/subscription/notification which is, quite frankly, the genius of the outliner.

    OmniOutliner 3 Pro is pretty expensive, but you can upgrade the free version (2.0) that came with your ‘pro’ mac (powermac/powerbook) to get a discount.

    Although this sounds like a commercial. I’m not anything to do with them – it’s just a tool I use all day long and love to bits.

  2. Amy

    I think you followed trackback to comment on my post about this one, but I was flying through blacklist deletions and lost it! Just want to say thanks again for a very useful post. I use Dave’s OPML editor to keep up the travel node at iPodder, but you’ve given me confidence to go beyond that.