HKPro.com - Features this unofficial resource for the serious student of Heckler and Koch. Provides a forum and also sells HKPro gear. - http://www.hkpro.com/
Chris's Unofficial H&K P7 Website - Offers information about the P7 series of semiauto pistols made by Heckler and Koch with an HK-4 annex. - http://www.hkp7.com/
Mark23 Owners Guild - Presents a library of information on everything for owners and enthusiasts of the Mark23 or Mk23mod0 SOCOM. - http://www.mark23.com/
Heckler and Koch USA, Inc. - Features this North American subsidiary which also distributes Fabarms. - http://www.hecklerkoch-usa.com/
HK91.com - Offers information on Heckler and Koch firearms, a message board, and gun rights data. - http://www.hk91.com/