mIRC is an Internet Relay Chat (IRC) client for Windows with an integrated scripting language allowing the creation of extensions.

[4] mIRC was created by Khaled Mardam-Bey,[5] a British programmer born in Jordan to a Syrian father and a Palestinian mother.

The scripting language can be used to make minor changes to the program like custom commands (aliases),[3] but can also used to completely alter the behavior and appearance of mIRC.

[3] Due to the level of access the language has to a user's computer — for example, being able to rename and delete files — a number of abusive scripts have been made.

[18] This led to changes being made in mIRC version 6.17: according to the author, $decode is now disabled by default, and various other features which can be considered dangerous are now lockable.