Today, Yahoo released the beta of a new site called Yahoo! Mash. Because it is currently an invite-only site, going to the link might now reveal very much, but Tech Crunch has some coverage and screen shots here. Now, normally I don't tend to talk much about my work or give my opinions about it other then to mention some new features coming out of Yahoo, but Mash is a little different in that I'm directly involved with it. I switched out of my previous group where I had been for the past few years to work on this project and be its engineering manager.
Mash is a strange beast and is different for different people. Some view it as a social network site. Some view it as a Facebook competitor. Some believe that it is a Y! 360 replacement. Mash is all of these and none of these.
At its core, Mash is your Yahoo! Profile with additional functionality often found in social networking site with a very wiki-like philosophy. Additional functionality can be obtained through "modules". Not only can you customize your profile, but your friends can also help you build it (with your permission) by editing the profile and adding new modules for you. We hope to open it up so that everyone can write their own modules to share with others, but until them we're giving people as much freedom as possible to customize the page. You will be able to edit and create your own CSS to make the page look however you like (or your friends can do it for you if you're not so artistically inclined. ^^;).
I hope people find the site to be both fun and useful. Keep an eye out for the Hot Potato (get it? mash...potato...) module that jumps from profile to profile! It's still in beta so we know there are some features that users are wanting. I encourage people to make suggestions on our suggestions board.