A longitudinal study was conducted in this research to examine member contributions in an Open Source Software User- Oriented Community (OSSUOC). Data were collected from both mailing-list archives and meeting minutes of a local Linux user group over a six-year period. Social Network Analysis and Web archive analysis were used to identify core contributors of activities in different categories. Member contributions were then measured based on the intensity, the breadth, and the continuance of participation across activities and years. The results suggest the importance of a balance between online and offline activities in an OSSUOC. Additionally, offline outreach activities play a more crucial role in stimulating the overall participation of an OSSUOC. The research contributes to the understanding of individual contributions and overall performance in an OSSUOC.