The confocal-line (CL) technique combines some of the characteristics of confocal-scanning microscopy with those of conventional-imaging methods. It is based on the introduction of line-shaped illumination and linear image detection, as an alternative to the current confocal-point (CP) approach. Although confocal only in one dimension, the proposed solution offers performance and features adequate to a variety of biological and non-biological applications and is also adaptable to an increased number of microscopical observations and measurements. The absence of moving components in the optical path and the use of electronic linear imagers permits flexible and fast operation that appears particularly relevant in many fields of basic and applied research. For instance, transmission, reflection and emission images can simultaneously be collected from the same area of the specimen, with slight adjustments to the optical setup. Useful extensions of CL microscopy to the field of spectral imaging are obtained with the introduction of a slit, a polychromator and an area detector, substituting for the linear imager. Prototype instrumentation has been constructed working from the cited principles and some tests have been performed on selected applications.