Software source code preservation plays a critical role within the scholarly ecosystem. Software is emphasized as an essential scholarly artifact, distinct from traditional research data and publications due to its evolving nature and complexity. Software Heritage, an international non-profit initiative, maintains the world's largest open archive of software source code, containing over 300 million projects and 19 billion unique files. The presentation outlines how this archive supports open science by offering universal, persistent access to software source code, thus enabling reproducibility, transparency, and enhanced collaboration in research. The presentation underscores the importance of connecting scholarly infrastructures with Software Heritage through standardized processes, such as the SoftWare Hash Identifier (SWHID), facilitating accurate citation, recognition, and long-term preservation. The talk concludes with a call to action advocating for policy-driven approaches, community engagement, sustainable infrastructures, formal academic recognition of software development, and an open-by-default stance for publicly funded software, ensuring comprehensive preservation of software heritage for future research and innovation.