Panic Software’s new Coda app offers a new approach to web site development, claiming to offer everything you need in “one window”.

The very first thing that struck me about it was the eye candy. Create a new site, fill in some of the server details and click “Save”, and the sheet you were filling in doesn’t slide up like most sheets do; it elegantly swishes out of view, flipping itself over in the process. It’s the kind of thing we’ve got used to seeing in Dashboard widgets, not desktop apps.

The second thing I noticed was the toolbar is not a toolbar, it’s a means of switching between modes. In fact, it’s not even customizable in the standard way. There are no other toolbar buttons other than those used to switch from one mode to another, and the search box.

There are lots of controls everywhere else though. Above and below the edit window you’ll see various contextual buttons and twiddles that change as you move between modes.

The code editor at the heart of the app is SubEthaEdit, which means it has Bonjour network sharing built-in. There’s a neat toggle button for switching the sharing on and off.

I haven’t yet got my head around the handling of CSS. It’s possible to create a .css text file and edit it by hand; it’s also possible to use the CSS mode to access a GUI for creating CSS using good-old point-and-click. The hows and whys of which system to use, and when, escape me for now. But as the title of this post says, this is just about first impressions.

So far I’m enjoying it. The eye candy is attractive without being too intrusive; the system of “Sites” for managing projects is nicely done, and the inclusion of entire HTML, CSS, Javascript and PHP reference books is an innovative and smart idea.

UPDATE:Steven Frank’s overview adds more context and is well worth reading before you dive into Coda.