The Nebelwerfer (German for "smoke launcher") was a multi-tube rocket artillery piece that was introduced during World War II. There were two variants, both towed pieces; one had six barrels and fired a 150mm rocket, whereas the other fired 210mm rockets but only had five barrels. The rockets (known as 'wurfgranate' or rocket shell) were unguided, and thus were ripple-fired in salvos of six (or five) to increase their chances of hitting their targets. The rockets were highly effective against unarmored vehicles and infantry, but their warheads were too light to do more than inconvenience full tanks. The maximum range was around 2.5 km for the smaller rockets, and 8 km for the larger. During the invasion of Sicily, American troops nicknamed the weapon the 'Screaming Meemie' for the screeching sound the rockets made. The first powder artillery, in ancient China, was rockets; the Nebelwerfer merely continued a trend that survives today in the M-270 Multiple Launch Rocket System and HIMARS systems in the US. The Soviet Union fielded their own version during World War II, the Katyusha, and that nickname is applied today to modern Russian rocket artillery pieces.
The original Nebelwerfer suffered from a problem that still haunts rocketeers today - the smoke trails left by the rockets made counterbattery fire very easy to target. Modern versions are mounted on vehicles to 'shoot and scoot' quickly to cope.