Read/Write Web, a top site focusing on what's happening in the business of web technology, has a look back at the evolution of the Web Office platform; office productivity tools that are accessible via the web.  They begin their retrospective at Writely, which later became Google Docs.  Writely is widely considered to be the first real web-based office application.  Prior to Writely and it's heavy use of AJAX, web tools weren't even approximating the experience of using a desktop application.

The article goes on to chronicle the changes and improvements over the last two years, as well as what this might mean for traditional desktop office applications like Microsoft Office.  It also looks at the impact of alternative publishing systems like Blogs and Wikis, which could also influence the office tools landscape as they gain in popularity.  If you're at all interested in seeing what alternatives there are to MS Office, hit up the article link below.