Compact compressors and refrigeration systems that can be used to cool computers, servers, and other electronic equipment. Each compact compressor or refrigeration system includes a compact, substantially enclosed hermitic housing having a simple geometry profile, such as a rectilinear profile, which enables the compact compressor or refrigeration system to be easily inserted within a slot, for example, of an electronic component such as a computer server. In one embodiment, a compact compressor is provided, which includes a motor-compressor unit within the housing, including a stator, a rotor disposed interiorly of the stator, and a compressor mechanism disposed interiorly of the rotor to provide a compact profile. In another embodiment, the housing includes the foregoing compact motor-compressor unit, and further includes a condenser formed within one of the walls of the housing and an evaporator formed within another wall of the housing such that the housing defines a completely contained, compact refrigeration system. Alternatively, in another embodiment, the housing may include only one of the condenser and evaporator, with the other of the condenser and evaporator configured as a modular component which is attached to the housing.