Website admin skins/themes clearly have a big market. Just see many different options for Drupal hosted on drupal.org or some nice commercial ones on themeforest.net (not Drupal specific). Administration themes are great when you'd like to separate your administration interface from your front-end. And several Drupal studies showed that many people need this separation to understand where content is managed and what does everybody else see of the site. Of course your mileage may vary and there are all kinds of sites where community participation is on a level that admin/front end separation is meaningless. The point of this blog post is not even administration themes, so let's shelve that discussion.
Websites often replace traditional web applications as well, when the "front end" of the website is already some kind of data input / management UI, where the data is usually not in the form of textual posts with comments tagged by topics. Navigation is not primarily search based because pages for different functionality in the site are not searchable in a traditional sense. Finally, menus are not built by the site builders but rather the application author, putting in menus and navigational elements via code suited for the application.
In Drupal, this kind of theming needs a different approach compared to traditional admin themes, because the web application will most probably not offer the usual Drupal admin functions. For this role, a theme more like the general ones of themeforest's admin looks fits more.
I was actually on the looks for such a theme for Drupal for some time now, because I have an itch to scratch here. I've been trying out all the regular admin theme suspects as well as other simple Drupal themes without much success covering my use case. I'm coming to this question from a web application developer perspective, based on my work with the Localization server. The interest in the server from open source as well as web based projects ticked up considerably recently and I've been putting some of my free time into generalizing that to a level that it becomes easily reusable for any software localization project. We are getting pretty close there, but one critical piece was missing. A matching look.
I've been playing around with different things in the past few months, and finally settled on doing something I've never thought I'll end up doing. Develop a web application theme based on Garland (uh-oh). Instead of starting totally from scratch, this let me reuse some of the great elements from Garland while doing away with some things I considered purely eye-candy. I did keep color module support so I ended up with almost all of Garland's image files duplicated. A this point, I'm not sure whether it should be kept as a Garland-based theme, or should live on its own. It is also in some ways a quick hack still on top of Garland, so it needs a bit more cleanup. I decided to share it with you early to get some feedback and maybe some other itch-scratchers even.
I've named this theme Curie after Marie Curie, keeping the famous-women naming scheme of Garland and Minnelli while deviating towards the technical field. The initial (rough) source is now available on the DRUPAL-6--1 branch of the theme.
Some screenshots for the curious:
Disclaimer: Curie is based on Garland and is the work of a guy who is primarily a developer (and has very limited graphics chops). It is not the top of all web application usability and is not intended to be so. I consider this to be better suited for this type of applications but your use of Curie is up to your judgement. I'm open for suggestions.