ALPS, which stands for Applications and Libraries for Physics Simulations, is a freely available package of open-source software. This software enables important scientific research and education in various areas of advanced physics research such as quantum computing. It is used by researchers in over 50 countries and has resulted in thousands of publications. This project will transition ALPS software development and maintenance from a project largely led by a single research group into a collaborative open-source ecosystem with many participating contributors, putting it on sustainable long-term footing. Steps to transition ALPS into an open-source ecosystem includes development of recruitment protocols, trainings, and clear management protocols. ALPS will become a broadly supported, distributed community effort with a clearer leadership structure. ALPS comprises a wide array of physics modelling software that enables studies of condensed matter and materials physics, quantum computing, atomic and molecular optics, quantum chemistry, and many other areas of physics and engineering. The project establishes infrastructure to sustain maintainability and the quality of the code base, establishes clear recruitment protocols and strategies, improves accessibility and documentation, and develops user training materials. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.