Abstract. Geometric Differential Evolution (GDE) is a very recently introduced formal generalization of traditional Differential Evolution (DE) that can be used to derive specific GDE for both continuous and combinatorial spaces retaining the same geometric interpretation of the dynamics of the DE search across representations. In this paper, we derive formally a specific GDE for the space of genetic programs. The result is a Differential Evolution algorithm searching the space of genetic programs by acting directly on their tree representation. We present experimental results for the new algorithm.