Software is networked,which is a fundamentally change brought by Internet. Carried byInternet, software as global resources provides plenty ofinformation services to the masses for every kind of applications.Software will be changed in many parts such as computation model,application pattern, products style and delivery model. Forexample, we need not purchase the total software but just pay therent for the usage over the Internet in the future just liketelephone service in our homes and offices. Networked softwarebecomes the core for connecting communication, data andcomputational resources. However, networked software systems arealso complex systems, and thus software development and softwarequality are troubled with software complexity. Softwareengineering is a systematic, disciplined, quantifiable approach tothe development, operation, and maintenance of software. Recentresearch achievements in complex networks introduce newmathematical foundations and software engineering methods forsoftware complex systems. Based on the discussion of softwarecomplexity, the research efforts on complex networks of softwaresystems are summarized, including topology properties, occurrencemechanism, evolution rule, complexity metrics and evaluation. Aconception is proposed in the present paper that software shouldbe considered in the context of network, in other words, softwaregrows in networks and network is a good method for characterizingsoftware. We hope this conception will help deepen ourunderstanding of the essential of software complexity.