A new update (1.3) is about to be relased, including a Mac version.
Picture:

Now if this isn't cool, tell me what is ^^
www.nevercenter.com <--- Find Silo here
Silo 1.3
Silo 1.3 follows in the Nevercenter tradition of frequent major upgrades with, among other new tools, the revolutionary Topology Brush. The tool allows users to sketch freehand lines on top of an existing mesh and automatically create new geometry based on the sketched topology.
“This is a major workflow improvement and could potentially cut down modeling time dramatically,” said Adam Cobabe, Artistic Director for Nevercenter. "Possibillities include retopologizing scan data, creating a low-res mesh from a high-res mesh and vice versa, adding clothing and reworking edge flow in problem areas.”
Other new additions in Silo 1.3 include a slide tool, shortest path selection, and drag and drop button placement for custom interfaces.
Silo 1.3 follows in the Nevercenter tradition of frequent major upgrades with, among other new tools, the revolutionary Topology Brush. The tool allows users to sketch freehand lines on top of an existing mesh and automatically create new geometry based on the sketched topology.
“This is a major workflow improvement and could potentially cut down modeling time dramatically,” said Adam Cobabe, Artistic Director for Nevercenter. "Possibillities include retopologizing scan data, creating a low-res mesh from a high-res mesh and vice versa, adding clothing and reworking edge flow in problem areas.”
Other new additions in Silo 1.3 include a slide tool, shortest path selection, and drag and drop button placement for custom interfaces.
Picture:

Now if this isn't cool, tell me what is ^^
www.nevercenter.com <--- Find Silo here