Editing Multiple rocket launcher (section)

===World War II===
[[File:Katyusha Rocket Launcher - Artillery Museum - St. Petersburg - Russia.jpg|thumb|BM-13 [[Katyusha rocket launcher|Katyusha]] (in service since 1941)]]
[[Image:T-34-rocket-launcher-France.jpg|thumb|American [[T34 Calliope]] (designed in 1943) in action]]
[[File:The British Army in Normandy 1944 B9593.jpg|thumb|A German Panzerwerfer [[Sd.Kfz. 4]] captured by the British during the [[Invasion of Normandy]] in 1944]]
[[File:385th Guards Artillery Brigade's 9K57 Uragan firing at the Totsky training ground (23-08-2018).webm|300px|thumb|Video of firing [[BM-27 Uragan]] in Russian service, 23 August 2018]]

The first [[self-propelled artillery|self-propelled]] MRLs—and arguably the most famous—was the [[Soviet Union|Soviet]] [[Katyusha rocket launcher|BM-13 Katyusha]], first used during [[World War II]] and exported to Soviet allies afterwards. They were simple systems in which a rack of launch rails was mounted on the back of a truck. This set the template for modern MRLs. The Americans mounted tubular launchers atop [[M4 Sherman]] tanks to create the [[T34 Calliope]] rocket launching tank, only used in small numbers, as their closest equivalent to the Katyusha. The Germans began using a towed six-tube multiple rocket launcher during World War II, the [[15 cm Nebelwerfer 41|Nebelwerfer]], called the "Screaming Mimi" by the Allies. The system was developed before the war to skirt the limitations of the Treaty of Versailles. Later in the war, 15&nbsp;cm Nebelwerfer 41s were mounted on modified Opel Maultier "Mule" halftracks, becoming [[Panzerwerfer]] 42 4/1s. Another version produced in limited numbers towards the end of the war was a conversion of the [[Schwerer Wehrmachtschlepper]] ("heavy military transport", sWS) halftrack to a configuration similar to the Panzerwerfer 42 4/1, mounting the 10-barreled 15&nbsp;cm Nebelwerfer.

Another German halftrack MRL system was inspired by the Russian BM-13. Keeping the Soviet 82&nbsp;mm rocket caliber as well as the launch and rocket stabilisation designs, it was developed into a system of two rows of 12 guide rails mounted to a [[Maultier]] chassis, each row providing the capacity for 24 rockets, underslung as well as on top of the rails, for 48 rockets total. This vehicle was designated [[8 cm Raketen-Vielfachwerfer]] (8&nbsp;cm multiple rocket launcher). As the launch system was inspired by and looked similar to the BM-13, which the Germans had nicknamed "''Stalin-Orgel''" or "Stalin-Organ", the Vielfachwerfer soon became known as the "''Himmler-Orgel''", or "Himmler-Organ".