At DTE Energy, we introduced Open Source practices to improve the performance of our 300- person software organization, achieving measurable improvements in code quality and reuse. We chose a community-based approach after a previous false start using tools and outside consultants. Two of our key principles for the transformation program were respect for the individual and creating a safe environment. We designed the program to support self-directed learning, with more skilled staff providing guidance as required. We also opened our technical environment, following an Open Source approach, to support sharing and communication. As always, cultural issues were critical to the success of the program. This paper describes the history of and lessons learned from our adoption of Open Source practices.