Available now by invitation only, Mash is similar to other online profile sites. However, it also allows users to make starter profiles for their friends and to leave their own profiles open to let other "trusted" users add content, noted Yahoo's Will Aldrich Monday in a blog post about Mash.
"You can customize your -- or your friend's -- profile with modules from a growing gallery of apps," noted Aldrich, who heads up the Yahoo team behind the development of Mash. "Of course, there are extensive privacy controls in Mash, and you set the boundaries that you're comfortable with."
He also noted that "Mash is still pretty raw -- there are bugs, and we haven't gotten to several of the features it really should have."
Aldrich did not say whether Mash will eventually replace Yahoo's existing social network, called Yahoo 360.
Michael Arrington, a beta user of the Mash network who blogs at TechCrunch, noted that Mash allows users to load modules like Flickr Real Simple Syndication and blog applications into their profile pages. The modules can then be moved by dragging and dropping elements, he noted.
"It also appears as though Yahoo intends for users to mash their information together from across the company's various properties, perhaps making Mash the main hub for Yahoo users," Arrington wrote. "While profile pages appear to have a pretty consistent structural layout (like Facebook), users can customize the design of their pages by changing colors and inserting background images (like MySpace)."
Mash also has a feature called Pulse, which are "Twitter-like messages" reporting all the activities a user's friends make on the site, Arrington added.
However, he noted that Mash lacks a mechanism to search across the network.
Microsoft logged 118 million unique visitors in August, Google garnered 116 million, and Yahoo pulled in 110 million during the month, according to Nielsen/NetRatings.