Is Roblox Crossplay?

Roblox supports full crossplay across PC, PlayStation and Xbox, so your group can play together whatever each of you is on. Progress and unlocks carry between platforms. It's free to play. Supports up to 100 players. Released in 2006.

Roblox is a massively multiplayer online platform marketed toward creators and players of all ages. It allows users to create their own virtual games using a variety of objects, which they and others can enter and socialize in. Games created on Roblox can be scripted using a sandboxed scripting language based on Lua 5.1 to affect events that occur in-game and create different scenarios.