A gang sheet build is a tool that can nest/place different sized logos on a sheet and hopefully taking up as little space as possible or placing as many logos as possible within the constraints of the sheet size.
Other than in placing logos on a sheet, this is often used in cutting and packing (although these are often rectangular packing problems).
Here is an example of the output from a gang sheet builder: a number of logos placed on a "sheet", taking up a little space as possible:
On my blog, you can follow along while I try to build my own gang sheet builder.