"Survivalism" (also known as "Halo 23") is the first single by Nine Inch Nails from their 2007 album Year Zero. The song is the third track on the album. The single was released digitally on the iTunes Store on March 13, 2007, and the CD and vinyl singles were released internationally on April 2, 2007.
On February 14, 2007, a clip of the chorus to "Survivalism" was first heard by fans calling the telephone number 1-310-295-1040, which was found by joining discolored numerals on the back of a tour t-shirt. FMQB reported that "Survivalism" would arrive at radio stations on February 27 with an add date of March 6, but 102.1 The Edge in Toronto, Canada debuted the song on February 15, and on the next day, it was officially played on radio stations across the United States. It was later made available on Nine Inch Nails' MySpace page.
As with "The Hand That Feeds" and "Only," the "Survivalism" multi-track GarageBand file was released by the band for fan remixing on March 13. It can be downloaded on the album's website.
In July 2012, Canadian house musician Deadmau5 did a remix of the song.