What is an OPML file

This morning I questioned the guys at Recruiting.com, was their Big Bad Blogroll in OPML this was in response to a post from a couple of days ago. Within minutes I got an email asking me to explain myself here we go.

OPML is basically a text file in an XML structure that is designed to provide structure to an outline. Wikipedia has a great page on the whole topic. But to save you a click here is their summary:-

OPML (Outline Processor Markup Language) is an XML format for outlines. Originally developed by Radio UserLand as a native file format for an outliner application it has since been adopted for other uses, the most common being to exchange list of RSS feeds between RSS aggregators.

The OPML specification defines an outline as a hierarchical, ordered list of arbritrary elements. The specification is fairly open which makes it suitable for many types of list data.

There are other places to go for information on OPML, Scripting News, developer resources, OPML.org (aka Scripting News), and the OPML 1.0 Specification.

From a blogging point of view an OPML file is a preferred method of transferring a collection of RSS feeds from one feed reader to another. Most RSS readers allow you to import and export your feeds into an OPML format, which facilitates the migration of tools for users but it also provides far more power.

Let’s say you have a list of bloggers who you want to share with another person, create an OPML file ask the recipient to import and now you both are subscribed to the same list. This would mean that the HR blogging community could create a complete listing of blogger and provide it to others to facilitate bulk subscriptions. I have started to prepare such a file, hence my question, that would classify all of the different HR blogs a bit like a directory, which is the other use of OPML. I have even started to hack together an online registration tool in PHP and MySQL that would allow you to subscribe to the OPML file, it is a long way from release as I am using it as a learning exercise. If you look at iPodder.org it is essentially a whole lots of OPML files. But once again this is only the beginning.

I wrote earlier in the year about the ability to deliver complete learning programs via OPML. This original post pointed to a post by Cameron Reilly on a similar but commercial idea. Essentially something that seems to have been forgotten in the whole podcasting hype is that Podcasting uses the enclosure tag in an RSS feed to point to other content, the podcatcher software then automatically downloads the file. But most RSS readers now understand the enclosure tag, some even automatically down load the file and with the addition of MIME types could run the required programs in the same manner as clicking on a link in a browser. Suddenly your eLearning environment can change radically, and not due to student blogging which seems to be the push.

First day in the class students are provided an OPML file that provides the details for the lecturers for the semester, they will blog and provide course notes, presentations, thoughts and opinions via their blog, the students will receive content automatically via their RSS reader. At the end of each lecture the podcast is also sent out using the same process. If the lecturer needs to communicate about something out side of the normal course then the blog provides this mechanism. Let’s take this a step further, it does not need to be a blog in the tradition sense that we are using now, it could just be a portion of a LMS, but that is a topic for another discussion. Even internally corporate type courses can be delivered using a similar method, and here the process can go over a much longer time frame.