skribbl - Word guessing based on drawing.
Cadbull - Cadbull is a website that comes with an advanced collection of CAD blocks and DWG design, facilitating architects and designers to get done with their projects efficiently.
LetsDraw.It - Guess and Draw, Drawing Battle, Pictionary, Copy picture - online drawing games where you can compare your skill with others.
DWGFREE - DWGFREE is an online platform that comes with a comprehensive collection of CAD blocks that can be downloaded without the need for registration.
gartic.io - Draw, guess, and win!
RealityMAX - RealityMAX is the most powerful free 3D design collaboration platform, 100% online. Cooperate remotely with your colleagues on 3D projects and easily share your work with clients. Create Web3D and AR experiences in a snap, without a line of code.