A tabletop system for digital high resolution and high sensitivity X–ray micro–radiography has been developed for small animal and soft tissue imaging. The system is based on a micro–focus X–ray tube and the semiconductor hybrid position sensitive Medipix2 pixel detector. Transmission radiography imaging, conventionally based only on absorption, is enhanced by exploiting phase–shift effects induced in the X–ray beam traversing the sample. Phase contrast imaging is realized by object edge enhancement. DAQ is done by a novel fully integrated USB–based readout with online image generation. Improved signal reconstruction techniques make use of advanced statistical data analysis, enhanced beam hardening correction and direct thickness calibration of individual pixels. 2D and 3D micro–tomography images of several biological samples demonstrate the applicability of the system for biological and medical purposes including in–vivo and time dependent physiological studies in the life sciences.