SketchUp (formerly Google Sketchup) is a 3D modeling computer program for a wide range of drawing applications such as architectural, interior design, civil and mechanical engineering, film, and video game design — and available in a freeware version, SketchUp Make, and a paid version with additional functionality, SketchUp Pro. SketchUp is currently owned by Trimble Navigation, a mapping, surveying, and navigation equipment company. The company was independent from 2000 to 2006 and owned by Google from 2006 to 2012. The program's authors describe it as easy to use. There is an online open source library of free model assemblies (e.g., windows, doors, automobiles, etc.), 3D Warehouse, to which users may contribute models. The program includes drawing layout functionality, allows surface rendering in variable "styles", supports third-party "plug-in" programs hosted on a site called Extension Warehouse to provide other capabilities (e.g., near photo-realistic rendering), and enables placement of its models within Google Earth.