Author summary As funders of scientific research, we have a unique knowledge of the challenges that researchers face in finding support for the many parts of their projects. Scientific software is a central part of the research process and is increasingly in need of investments to ensure continued advancement and progress. Here we draw on our experiences as funders to provide guidance and considerations for funders and other community members interested in supporting scientific software. We address specific issues related to software, including contributor community development, governance, sustainability, and diversity and inclusion.