Large-scale software projects are interesting examples of human-made complex systems. The complexity of these systems can be reflected both in their structures and in their development processes. Due to the wide adoption of open source practices using online infrastructures, both the software development process and the final software structure can be traced in an easy way. Thus, a large-scale data set about software projects can be obtained, making an in-depth study of software projects possible.

During the last decade, complex networks have been widely applied to analyze the topological structure and dynamics of software projects. Many shared physics-like laws of such software projects—such as scale-free, small-world, and fractal properties—have been revealed.

The objective of this Special Issue is to provide a comprehensive collection of cutting edge research work on the application of complex network theory, and techniques to explore software projects. Original research articles presenting novel in-depth fundamental research are welcomed, along with review articles discussing the current state of the art.

Potential topics include but are not limited to the following:

• Characterizing software projects, software ecosystem, and service ecosystem from a complex network perspective
• Network evolution models for analyzing the growth and evolution of software projects, software ecosystem, and service ecosystem
• Software optimization using techniques in the field of complex networks
• Bad smell detection from a complex network perspective
• Clone detection from a complex network perspective
• Source code (or API) recommendation using techniques in the field of complex networks
• Concern, concept, and feature localization and mining using techniques in the field of complex networks
• Analysis of developer-user relations in open source software communities
• Analysis of bug dependency networks
• Network-based software metrics
• Network-based prediction of software quality or process problems (software defects, modularity, stability, etc.)