Eurorack is a standard developed by Doepfer Musikelektronik in 1996. It was largely based on the "Euro card" standard, which was mostly used for professional electronic equipment. Today eurorack is the most common standard for modular synthesizers.
Vertically it occupies the same space as a 3U (3 rack units) enclosure in the 19" rack standard (the most common rack standard for most kinds of equipment). Horizontally units typically called HP (Horizontal Pitch) are used, where each HP is equivalent to "one screw hole" in the rails. 19" rack enclosures for Eurorack are available, typically containing 84HP. Each mounring-rail usually has a slit for inserting an strip of metal with screw-holes. These holes are typically M3 but may in some exceptions be M2.5.
Electrically, eurorack specifies that modules receive ±12V and (optionally) +5V from a common power supply in the rack. In modern modules, 5V is rarely used. Eurorack also specifies that signals are exchanged between modules via 3.5mm mono jack cables. These can be audio signals, control voltages, trigger, gate or clock signals, or sometimes video signals.
Eurorack front panels can easily be manufactured with a laser cutter or water jet, or can simply be printed circuit boards.
Eurorackskinner er egentlig skinner fra eurocardstandarden. Disse dukker ofte opp i elavfall.
De finnes også hos diverse elektronikkleverandører under navnet "horizontal rail"
Det finnes flere varianter, de som er ment å ha fremme på eurocard kabinettet, og de som er ment å ha bak. På de som er ment foran får man lang og kort "leppe" og på de som er ment bak får man de som er ment til isolasjonsstrips mellom bakplanskortet, og de som er ment uten.
Schroff er en produsent av slike og de har en katalog: http://web.schroff.de/style/catalogues/ep23/e/05_e_desktop_cases.pdf
Elfa: https://www.elfadistrelec.no/no/gjenget-innsats-431-3mm-stal-nvent-schroff-34561-484/p/11018335
Farnell: https://no.farnell.com/schroff/34561-484/threaded-strip-m3-84hp-431-3mm/dp/2707190