As GecT mentioned its a sculpting package. I personally much prefer it to zBrush as it is a fully 3D way of sculpting high detail 3D models as oppsed to zBrush's '2.5D' approach.

It doesn't have all the features of zBrush as of yet, but it is certainly catching up each version tha comes out.

It is also far easier to pick up as it feels like a more general 3D package like Maya or Max.

Chris