A review of the possible future HEP Accelerator Projects

<!--HTML-->The review, as already invited for presentation at the recent International Conference on High Energy Physics (ICHEP2010), covers all accelerator projects presently envisaged for HEP in the near and mid-term future. After a brief description of the major motivation, issues and necessary R&D of each project, it specially emphasizes the synergies between the different projects and their R&D issues, pointing out their complementarities and the efficient collaborative approach to address them. It finally summarizes the relative schedule of the various projects in their different phases, pointing out their global interdependence.