Among the light metal alloys, magnesium is the lightest structural material with a density of 1.74 g/cm³ and many attractive physical and mechanical properties combined with processing advantages. Therefore, it represents a very attractive material for a large amount of applications from main user automotive industry up to other industry fields like sport, robotic and electronic industry. But the usage of magnesium alloys in more complex applications is limited by insufficient properties regarding the ductility, corrosion and creep resistance. Additionally, the high reactivity of magnesium alloys leads to an increased tendency of contamination. In this regard, the paper deals with some general aspects of magnesium alloy development and casting as well as some other production technologies for magnesium alloys with improved properties and for several applications. An emphasis is put on new magnesium-lithium alloy systems with lower density, improved ductility and corrosion resistance. The basic component of metallurgical processing is a magnesium-suitable furnace system which is designed modularly with universal, adaptable components and automatic pressure metering technology. It is used in a wide range of casting processes like chill casting, cold chamber die casting, continuous casting and break-mould casting. Further applications are methods of rapid solidification technology. In the powder metallurgy and spray casting a microstructure with fine and homogeneous phase distribution is generated. Based on the represented processing technology new magnesium alloy systems with lower density, improved ductility and corrosion resistance will be shown. A special peculiarity of magnesium alloys is their application in the medicine sector where they are used as implant materials for surgery.