Tom Holkenborg, known as Junkie XL or occasionally JXL, is a Dutch multi-instrumentalist, producer, and engineer. He uses the name JXL in cases where the term "Junkie" might cause offense.
Holkenborg first collaborated with Klaus Badelt for the Catwoman movie as a composer and producer for additional music. He did some programming for Hans Zimmer score for The Dark Knight Rises. He collaborated with Zimmer again for Batman v Superman: Dawn of Justice.
Holkenborg was originally set to compose the Justice League movie soundtrack, but he was later replaced with Danny Elfman by guest director Joss Whedon. His work is restored for Zack Snyder's Justice League.
Other works include Megamind, Paranoia, 300: Rise of the Empire, Mad Max: Fury Road and Deadpool.