Her name is Cortana and she's bringing plenty of underdog attitude to the competition for the title of best digital personal assistant. Who can best fill out your calendar, call a friend or find the nearest French restaurant on command? We shall see.

Cortana's home on the Windows Phone doesn't have the cachet of Siri's hipster digs on iPhone. In a world in which Apple and Android phones dominate, Cortana's chances of widespread adoption appear slim.

Pixelated hero: Cortana, from the game series Halo, is also the name of the new voice of Windows phones.

But Cortana is eager to please, oozing friendly confidence compared with sometimes-aloof Siri. Plus, Cortana gets extra geek cred for drawing her name (and some of her conversation topics), from the artificial intelligence character in the Halo video game series.

"We built Cortana to really model a real-life human personal assistant," says Greg Sullivan, director of Windows Phone product marketing at Microsoft.