Software reuse is essential for improving the productiv- ity and quality of software projects. One of the key issues to promote the adoption of software reuse in companies is the development of effective repositories of software com- ponents. It is also very important to have good methods for searching and retrieval of the components. Clustering tech- niques can help by providing a visualization of the reposi- tory of software components as well as in helping to refine the searches by grouping together similar components. In this paper we quantitatively compare two clustering tech- niques, namely, self-organizing maps (SOM) and growing hierarchical SOM (GHSOM) for clustering a repository of classes from a Java API for building mobile systems. The performance measure was the quantization error. The simu- lations have shown that GHSOM outperforms SOM in these tasks. GHSOM is more suitable for this task because it is a constructive technique, which is an advantage in tackling the growth of the repository of software components.