Computational software plays a key role in scientific research. However, development and use of this software is hampered because there is no well-defined way for authors to receive credit or professional recognition. The SAGA project brings together an interdisciplinary team from the Social, Library, and Computer Sciences to illuminate the technological and cultural barriers to effective software citation. We seek to develop a usable software tool for citation of open source software that completely describes the software environment and attribution for contributions from multiple authors. Our work is particularly oriented towards codes and scientific culture in geodynamics research, but we hope to extrapolate lessons learned to other fields.