Developer Console, Roblox Wiki

The Developer Console (shortened as the Dev Console or simply the console) is a built-in GUI used for a place. The console can be accessed in any place by pressing F9 on a standard keyboard, or typing "/console" in the Chat. The console displays output messages from the client. If the console is accessed by the place's creator, the console also has a server tab in which it displays output messages from the server and allow the creator to run code from the server. This section is a trivia section

Developer Products Documentation - Roblox Creator Hub

Terrain Editor Documentation - Roblox Creator Hub

Why are these not in game (found them from official wiki) : r

Explorer Window Documentation - Roblox Creator Hub

Outdated Dev Console Image - Documentation Issues - Developer

Errors on the developer console without justification? - Scripting

Developer console isn't showing server log in my own game - Engine

Roblox Developer Console [FromLegoUniverse's Edition] - Creations

Developer console script rate increases indefinitely - Engine Bugs