Should web-based content creation tools also have a desktop installation option?

SiteJazzer lets you bring your web sites alive with interactivity. In doing so you don’t have to install anything on your computer. You simply get a SiteJazzer subscription, log in and start building a jazzer. Your entire content creation activity is online.

Contrast this will tools like Microsoft Word or Adobe Photoshop. These are software packages you install on your desktop (or laptop) and work away when you are ready. There is no need for internet.

Do you believe content creation tools should provide both online and desktop access options? Any thoughts or ideas?