rm3 is not just a blog engine, but it's not quite an enterprise CMS. Conceptually, it is to Drupal as Ghost is to WordPress.
rm3 is able work as a blog, a wiki, a photo archive, or some combination of those... and more.
rm3 has blog-styled views such that you can post a series of dated blog articles and view them as such. But every entity on the site has a history, like how a wiki works. Like some of those enterprise CMS systems, you aren't restricted to just creating a mere list of posts.
rm3 has rapidly improving support for media: It supports photos, but it also supports SVG vector graphics and audio files.