ThomX is a project of a Compton source in the range of the hard x rays (40 - 80 keV). The machine is made up of an injector Linac, a storage ring where the electron bunch collides with a laser pulse accumulated in a Fabry-Perot resonator. The final goal is to provide an x rays average flux of 1012-1013 ph/sec. Different users are partners in the ThomX project, especially from medical science and cultural heritage. Their main goal will be the transfer of all the experimental techniques developed on big synchrotron rings to these more compact and flexible machines. The project ThomX has already been recently funded and will be located on the Orsay University site.