ESER is an abbreviation for Einheitliches System Elektronischer Rechenmaschinen (German for standardized system of electronic computers), a term used in the GDR for ES EVM computers produced according to a treaty between the members of Comecon signed on December 23, 1968 covering the development of a standardized computing system.
ESER was also the name for computers developed by this standard. Most ESER Computers were named ЕС (which is Cyrillic for "ES") followed by a four digit number, e.g., EC 1055, often also called ESER (e.g., ESER 1055). Robotron also produced minicomputers, whose names started with "K" (Kleinrechner for "minicomputer").
The ESER systems were in operation in GDR until 1995.