Since 2010, the international JEM-EUSO (Joint Exploratory Missions for Extreme Universe Space Observatory) Collaboration has been developing an ambitious program with the support of major International and National Space Agencies and research funding institutions, to enable UltraHigh-Energy Cosmic Ray (UHECR) and High-Energy (HE) neutrino observations from space. Its main objective is to develop a large mission with dedicated instrumentation looking down on the Earth atmosphere from space, both towards nadir and/or towards the limb, to detect the Extensive Air Showers (EAS) initiated by such particles in the atmosphere. This strategy is intended to complement the observations made with ground-based observatories, by allowing a significant increase in the exposure at the highest energies, and achieving near-uniform full sky coverage, as part of the global effort to better characterize the phenomenology of UHECRs, discover their sources and understand their acceleration mechanism. In the last decade, the JEM-EUSO Collaboration successfully developed five intermediate missions: one ground based (EUSO-TA), three balloon-borne (EUSO-Balloon, EUSO-SPB1, EUSO-SPB2) and one space-based (MiniEUSO), and also benefited from the experience gained by the space mission TUS. Important studies for a full-scale mission have also been carried out, namely K-EUSO and the stereo double telescope Probe Of Extreme Multi-Messenger Astrophysics (POEMMA), to be considered for a NASA Probe Mission in the next decade. The technical and scientific achievements of this rich and manifold program are reported on, as well as the scientific objectives updated in the light of the knowledge gained from the previous missions, and additional scientific objectives accessible to such unique technology. Finally, the near-future developments of the JEM-EUSO Program are briefly presented, with the continuation of the Mini-EUSO observations and the new balloon-borne mission PBR.