DAVID-laserscanner is described as 'DAVID is a software for 3D laser scanning. All you need to build a 3D scanner is a PC, a camera (e.g. a webcam), a background corner, and a laser which projects a line onto the object you want to scan'. There are five alternatives to DAVID-laserscanner for Windows, Linux and Mac. The best alternative is ReconstructMe. It's not free, so if you're looking for a free alternative, you could try 3D Underworld or SLStudio. Other great apps like DAVID-laserscanner are DAVID-Shapefusion (Freemium) and FlexScan3D (Paid).
Structured light scanner is a tool to reconstruct point cloud from series of images lit by patterned light. As showing in the following image, patterns are projected to the object in the grid manner. Each cell in the grid has a unique sequence.