On December 30th, the team at LDraw.org released the newest parts update, 2017-01. According to the website, the new release adds 717 new files to the library, which includes 509 new parts and 33 new primitives. There are also updates to the configuration files for colors.
For those not familiar with LDraw, it is an open standard for defining parts used by a number of LEGO CAD programs. The open nature of the standard allows for numerous parts authors, including those who model 3rd party parts such as Big Ben Bricks wheels. Parts are reviewed before release to ensure compatibility with the standard and conformance to the actual part. CAD programs using the LDraw format are used by many modelers to create virtual MOCs and instruction sets. Having been around for over a decade, the LDraw library contains many parts not found other virtual building platforms, including parts that have been long retired, but that may be available to builders via BrickLink or other 3rd party sources.
Check out the LDraw.org website for more information, and enjoy the New Year!