  We present XMM-Newton studies of the total mass, gas density, temperature and
entropy profiles in nearby hot and cool clusters, together with follow-up
observations of distant clusters from the SHARC Survey. The observed structural
and scaling properties are compared with the predictions of the self-similar
model of cluster formation. These data indicate that clusters do form a
self-similar population down to low mass and up to high redshift, and give
support to the standard picture of structure formation for the dark matter
component. However, deviations from the standard scaling laws confirm that the
specific physics of the gas component is still insufficiently understood.
