First of all, a definition of Tumblelogging from Ozimodo's website

Tumblelogs are quick-and-dirty. They are loosely structured and used to share various iotas of interest. Throw a link log, a moblog, a quote blog, and a code blog (colog? quoblog?) into a blender and out pops a delicious, fat free tumblelog.

My personal favorite example of a tumblelog is Projectionist and there's the site of the creator of Ozimodo (Chris Wanstrath). There are many others out there.

On to the CMS. Without waxing too wordy about what CMS for tumblelogging should do, I'll provide a quick list and say that Ozimodo does what it should do well.

• Post types - this is the key difference between blogging and tumblelogging. With a blog all posts are, well, posts. With a tumblelog, a post could be a photo, a quote, some code, IRC or IM snippets or anything else you can imagine. This is handled nicely in Ozimodo.
• Tags - it has tags.
• Flexible templates - If you're going to do much customization of your Tumblelog, you'll definitely need to know some HTML and it would be nice to understand a teeny bit of Ruby to use the rhtml templates. None of the configuration for Ozimodo is done in the admin interface, it's all handled with .rhtml template files.

Ozimodo is written in Ruby on Rails and, like pretty much every Ruby on Rails app it is simple to install. The process is download, create empty database, edit 2 lines in config/database.yml, type 'rake migrate' and you're done.

Attached to this article are several screenshots of Ozimdo in action, including the admin interface. It comes highly recommended as a good (and the only) niche CMS created for Tumblelogging.

Eribium has been out for a very short time--as of this writing there have been under 250 downloads, but already looks like a promising option as a CMS for fairly simple websites. In general, Eribium can create pages based on a global template and handles uploads and file attachements nicely.

Where Eribium really shines are in the design--it's very polished, the admin looks great and the default themes (ported from Typo) are also very nice. It also does a really good job with the details. Check out the screenshots attached to this article for some visuals, but to list them, some of the coolest parts of Eribium are:

• Spell check - a la Gmail. Inline, preconfigured and very nice.
• Good control over feeds
• Have I mentioned it looks good yet? Well, it does.
• Tagging
• Nice use of Ajax in a few key areas.

The installation was painless. On a server that was already running Rails 1.1 it took me less than five minutes from start to finish to get it running. The steps are (like most Ruby on Rails applications) download, extract, create empty database, run rake migrate and you're done.

If you're looking for a powerful CMS, this probably isn't the best choice yet, but for a simple site Eribium is worth a look.

Something I've debated is whether to use an all-in-one CMS and customize it to do everything or to find (or write) a CMS that was created specifically for the task at hand. Showcase, written by Kyle Maxwell in Ruby on Rails, is one of the latter--it does an excellent job at what it was intended to be, a CMS to manage a portfolio.

Click here to view a screenshot of the Showcase admin interface

The Showcase admin allows you to manage several things, the name, subtitle, stylesheet, JavaScript behavior of your websites, as well as the users, pages and projects (both of of these sections can be renamed) and files attached to the site. Within a specific project, you can edit the name, description, version, thumbnails and attachments associated with the project. The admin interface makes use of Ajax in all the right places--editing and adding to the site is simple and fun.

Once you've got your data in there, Showcase produces an entirely unstyled site--it's up to you to create the CSS and there's no default template. While I think a default template or style would be nice, it's really not a bad idea not to have one--this guarantees that every Showcase site will look different.

Installation is very straightforward if you have Rails set up on your server. Basically you check it out of svn, create a database, tell showcase what it's called, type rake migrate and you're done. One caveat is that at the time of this writing Showcase requires Rails 1.0 (not 1.1) so make sure you freeze Rails 1.0 in vendor/rails.

If you're looking for a good, free CMS to manage your portfolio and don't mind writing a little CSS, check out Showcase.