A better understanding of the key to successful open-source software (OSS) development continues to motivate research. Aligned with work that builds on the notion that an OSS development is tightly interrelated with its social environment (i.e., the OSS community), this study examines the relationship between interproject structure and OSS project success. OSS project success is reflected in two forms: popularity and knowledge creation. Extending the extant OSS literature, we theorize a contingent role of interproject connectedness. In particular, we posit three points: (1) an OSS project with more structural holes achieves higher popularity; (2) an OSS project with fewer structural holes yields higher knowledge creation; and (3) these two relationships are enhanced by an increase in project maturity. Using a dataset longitudinally collected from SourceForge.net, we found that OSS projects with widespread connectedness are more popular. This is especially so for those OSS projects in the mid-mature stage. We also found that OSS projects with a cohesive network achieve higher knowledge creation, irrespective of their maturity. Findings from our study can contribute to OSS literature by identifying OSS projects that are more likely to be successful.