The Slip (also known as Halo 27) is the eighth major studio release by American Industrial rock act Nine Inch Nails. The album was released free of charge on May 5, 2008 via digital download on the official Nine Inch Nails website. The album was released on CD in the United States and Canada on July 22, 2008. The album was released as a six-panel digipack which contained (in addition to the album itself) a 24 page booklet, a sticker pack, and a DVD with live performances of 1,000,000, Letting You, Discipline, Echoplex, and Head Down. This package was limited to 250,000 numbered units worldwide The album was made available without any prior notice or advertisement, and in a similar fashion as the band's previous release, Ghosts I–IV, released two months earlier. The album was produced by Trent Reznor alongside Atticus Ross and Alan Moulder. The album features vocals and traditional song structures, unlike its 2008 counterpart Ghosts I-IV. Much like Ghosts I-IV, the album was released under a Creative Commons license, allowing fans to remix and reuse all or part of the album non-commercially. A tour for the album, entitled "Lights in the Sky 2008", began in late July and took place over most of North America and South America. A free download is available from the following URL: http://theslip.nin.com/ User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.