  The CALICE collaboration is currently developing engineering prototypes of
electromagnetic and hadronic calorimeters for a future linear collider
detector. This detector is designed to be used in particle-flow based event
reconstruction. In particular, the calorimeters are optimized for the
individual reconstruction and separation of electromagnetic and hadronic
showers. They are conceived as sampling calorimeters with tungsten and steel
absorbers, respectively. Two electromagnetic calorimeters are being developed,
one with silicon-based active layers and one based on scintillator strips that
are read out by MPPCs, allowing highly granular readout. The analog hadron
calorimeter is based on scintillating tiles that are also read out individually
by silicon photomultipliers. The multi-channel, auto-triggered front-end chips
are integrated into the active layers of the calorimeters and are designed for
minimal power consumption (power pulsing). The goal of the construction of
these prototypes is to demonstrate the feasibility of building and operating
detectors with fully integrated front-end electronics. The concept and
engineering status of these prototypes are reported here.
