In January 2012, Springfield Armory announced a new variant, marketed as the XD-S. The 'S' represents the single-stack magazine used, providing a slimmer grip. While sharing many features with the original XD and XD-M, the XD-S included a new pre-set trigger and a disassembly fail-safe, neither of which were available in XD or XD-M models.
Springfield Armory’s XD family of pistols, to include the XD Mod 2, XD(M), XD-S and XD-E, provide some…niche options…in the striker fired pistol market – options like thumb safeties, grip safeties, and grip “zones”. But they’re not illegitimate or wholly unworthy guns. Wilson Combat BW Carry, Springfield EMP 9mm, Dan Wesson Guardian .38 super, Sig P239 9mm, Springfield XDM .357 SIG, Sig P 938, Beretta PDX Storm 9mm, Smith AND WESSON Shield 9mm, Ruger .357 Vaquero, and a bunch of fine rifles and shot guns.