ODE Toolkit is a program for solving and teaching Ordinary Differential Equations. Over the past five years, CODEE has employed students at Harvey Mudd as developers. Unfortunately, weak architectural foundations and insufficient documentation have led to an unwieldy code base and significant development overhead. Our primary goal is to apply standard software engineering principles to reduce the burden of maintenance and upgrading. Additionally, the code will be prepared for open-source release to encourage the use and development of ODE Toolkit.