Roblox - Reimagining the way people come together.
HiberWorld - HiberWorld is a website that allows you to make and play 3D levels for speedrunning
KoGaMa - Kogama is a Massively Multiplayer Online, Sandbox, City-Building and Adventure-based video game.
Blockland - Blockland is a non-competitive multiplayer sandbox-style construction game. It's kind of like playing with legos on the internet.
Brick Hill - Brick Hill is the ultimate building block game, allowing you to push the limits of digital bricks and make your own games.
Minecraft - A block-building game that allows you to create and explore entire worlds from scratch.