Wikis are admirable tools for the collaborative editing of documents. But many of them lack features that make blogs such a participatory success.

Participation on wikis focuses on document editing. But what about other types of participation? This is where wikis generally fall short.

Let's say that you're interested in the documents on a wiki, but have no intention of pitching in to edit them. However, you have some knowledge of the topic and would like to make a comment. Or maybe you might eventually do some edits, but in the meantime want to record your thoughts and get responses from others. In addition, you'd like to bookmark the document on Del.icio.us or other social boomarking sites. Also, it would be useful if you could tag the document, and search the entire wiki with a tag cloud. (MediaWiki has categories, but no clouds.) Better RSS alerting of document revisions - and comments - would also be welcome. These are just a few ways in which wikis could be improved.

These features, often available on blogs, could usefully become more common on wikis. With these features added, wikis might become useful tools for more than editors and readers. They might attract broader participation in the form of interested afficionados who want to comment on, classify, bookmark and track the documents.

There is some development in these areas, especially as plug-ins or extensions for the wiki software. WikiMatrix gives some idea of what's going on, though of all the features I've mentioned it includes only RSS/Atom feeds and commenting in its comparison grid. And it doesn't differentiate between the idiosyncratic kind of Talk namespace available with MediaWiki and simple text-based footer comments available with other packages.

I'm pleased that a MediaWiki developer is in the process of creating an extension for threaded footer comments. As the author states, "The idea that everyone can edit any page on a Wiki is great for collaboration and refinement of ideas, but many people are afraid to touch another person's text or learn a new commenting system. Most people simply want to type their thoughts into a text box and have it appear at the bottom of a page of content. Agreed.

What about commenting on the paragraph level? Interestingly, there is work being done in the blog world that might be applied to wikis. Check out the annotated edition of the Iraq Study Group Report to see the paragraph-by-paragraph commenting system that might (in my view) be laying the foundation for future edits - of course, not of this particular publication, but potentially of others. This experiment offers a more useful commenting layout than the one used by Lawrence Lessig to revise his book Code and Other Laws of Cyberspace. Wikis can easily allow paragraph-by-paragraph editing, but not commenting. Combining these two features could make for a very useful tool. And for those wiki editors who want to keep out comments, the feature could be optional.

Wikis and blogs could benefit from incorporating each others' features. This could move us toward a truly full-featured integrated publishing platform in which the best of both systems are available. This, in turn, could lead to the type of library Web site that I envision.