Script developers had to get smart. They had to find "backdoors" or use RemoteEvents/RemoteFunctions to trick the server into doing what they wanted. The "c00lgui FE" was the community's attempt to adapt the classic, easy-to-use interface of the old c00lgui to this new, stricter security environment.
Here is a look back at the phenomenon of c00lgui, the technical shift of FilteringEnabled, and why this script hub remains a legend in the community.
: Features designed to circumvent certain game restrictions or security measures. How to Use Obtain the Script
Using unauthorized hubs like this violates the Roblox Terms of Service , which can lead to permanent account bans.