The identification of potential high-performance propellant combinations is based on a fundamental analysis of the governing parameters. Its development requires the establishment of its safety and handling characteristics and its thermodynamic decomposition and explosive properties. After the identification of hydrazinium nitroformate (HNF) as a promising new oxidizer, the development of a new composite solid propellant based on HNF and energetic binders such as glycidyl azide polymer (GAP), poly 3,3-bis(azidomethyl)oxetane, poly 3-nitromethoxy-3-methyl oxetane (polynimmo), or poly glycidyl nitrate (polyglyn) was started. A pilot plant for the production of HNF has been constructed and many of the properties of HNF and HNF/aluminum (A1)/GAP propellants have been established. Initial development tests show that HNF looks suitable as a propellant oxidizer, while initial tests with HNF/A1/GAP confirm the expected increase in performance over existing composite propellants. Impact and friction sensitivity have been determined for HNF and HNF-based propellants. Areas that are still open for investigation are also addressed. This article gives a comprehensive overview of the status of this development.