The label was founded by Ulex Xane and initially specialised in underground experimental and industrial cassettes. Roger Richards became involved in 1987 and eventually became the label’s director after Xane's departure.
Extreme has released CDs and tapes by artists such as Non, Orchestra of Skin and Bone, Paul Schütze, Muslimgauze, Social Interiors, Makers of the Dead Travel Fast, Jim O'Rourke, Elliott Sharp, Shinjuku Thief, Christoph Heemann, Otomo Yoshihide, Kato Hideki, and Big John Duncan. Extreme is also noted for being one of the first record labels, along with the American label RRRecords, to bring the work of the Japanese noise artist Merzbow to Western audiences and, in 2000, released the Merzbox, a 50-CD retrospective.
In March 2008, Extreme announced three new releases: The Massacre of the Egos by The Antripodean Collective (XCD-064), Maju-5 by Maju (XCD-063), and A Ritual That is Incomprehensible (to the smile of Pauline Oliveros) by Claudio Parodi (XCD-062).
Coming up in September and October 2008 were the following releases: XCD 065, Terminal Sound System: Constructing Towers; XCD 066, The Antripodean Collective: Funcall; and XCD 067, Claudio Parodi: The Mother of All Feedback.