CoreScript

The first example of a corescript in 2011, used to fix a bug where the UI would be stretched.

Corescripts are essential to make clients operate and function in modern ROBLOX.

The first appreances of Corescripts in the client were in 2011. Originally, they were streamed into the client by asset files, which were signed using the rbxsig format. In 2014, this system was changed to allow for "local corescripts" (which allowed for the corescripts to be stored locally, in the content/scripts folder.

There are also Lua virtual machines in ROBLOX's engine. There are threads with different identities can be run with different Lua virtual machines, so that user scripts are not mixed with scripts authored by ROBLOX. There are currently only two virtual machines, one for CoreScripts and other threads that have RobloxScript access and another for all the other threads. In studio builds, there is a third virtual machine used for studio plugins.

Some behaviors to note with corescripts are:

• The scripts have the `RobloxScript` context.
• There are other corescript signing formats besides rbxsig, which are noted in the signatures page.
• Corescripts are executed in its own Lua virtual machine.

Official corescripts can be found in the ROBLOX GitHub Repository.