RSS allows web sites to easily syndicate and share content with people and "other systems". Once somebody subscribes to your "RSS Feed" through their "RSS Program", they've got a "live link" to you: As soon as you update your site, they know about it, and can read some or all of what you just wrote. We Mac OS X users are very fortunate to benefit from a rich developer community around RSS.
DrunkenBlog interviewed a few key Mac OS X "RSS Program" developers on the future of their applications.
A key line of questioning revolves around Apple's recent involvement in the field by building RSS-capabilities into the future version of their own web browser, Safari.