[en] Energetic particle populations are important constituents of solar, circumplanetary, interplanetary and distant heliospheric plasma structures, and at the same time provide valuable tools for testing models of galactic and universal acceleration and propagation processes. Although both the maximum energies and the variety of plasma processes are restricted by the relatively small size and energy supply of the solar system, these limitations are partly compensated by the superior spatial, temporal, directional and charge state information available for these particles. Both in situ and remote sensing observations contribute to our understanding. Recent advances in these fields will be reviewed, and the expected impact of current and future missions discussed