The latest version of Microsoft's Web-based RSS Aggregator, Start.com, has just been released. Microsoft first released a prototype in early March 2005 - my coverage here. Start.com is like a mix between MyYahoo and the new Google Personalized Homepage. It enables users to subscribe to RSS feeds and it is closely integrated with search. Here are some of my initial impressions:

- As per the first time, Start.com allows you to add RSS feeds to a show/hide menu bar on the left. They've gotten rid of the horizontal category banners though and added the categories to the left menu (Business, Entertainment, etc). They've also added favicons, which is a nice touch.

- It's not dissimilar to the recently announced Google Homepage, but unlike Google, Start.com has RSS subscription functionality and ability to save searches. So 1-nil to Microsoft. As for Yahoo, they still have the most comprehensive portal and they've been using RSS feeds for some time now. So I still view Yahoo as the market leader in this little battle for the best 'Web 2.0 portal' (to coin a phrase).

- Start.com is optimized for the IE browser - what happened to the Firefox support?

- If you go to www.start.com/3/ you then have to answer 5 questions in order to access the actual Start.com homepage, which seems to be a method of showing off their integration with search. Alex Bosworth suggested over at Greg Linden's that "They are trying to get the cache of Google by making their page 'elite'". Hmmm.

- Overall, it's certainly a more impressive effort than Google's, but there's a long way to go before they can compete against 'real' Web-based RSS Aggregators like Bloglines or Rojo. For a start (no pun intended), they should add OPML support so that users can upload their existing feeds. But even if Start.com had that, there's no obvious way of organizing all that information (no folders, tagging, etc).

As I suggested in my recent post - On Interfaces: Rojo, Bloglines, My Yahoogle - Microsoft, Google and Yahoo will all need to change their interfaces to scale up the amount of RSS feeds their users can track. Or will search be the key driver to these portal pages, instead of RSS aggregation?

Perhaps there will always be two classes of web-based RSS Aggregators - the full-featured ones like Bloglines and Rojo, and the homepage/portal ones which focus on search and news first and RSS feeds second.