Focus: Multiparadigm Programming Focus: Multiparadigm Programming Focus: Multiparadigm Programming

USER INNOVATION AND customercentric development are hot topics in software and almost all service sectors, manifested by growing interest in crowdsourcing and user-contribution systems.1 However, success stories of companies that have switched from a traditional closed-source to an open source software (OSS) business remain scarce. Access to source code will likely increase—especially in commoditized software markets—but without the software being released as OSS. Companies are becoming more comfortable working with inbound OSS and adopting OSS-like processes. For certain types of products and vendors, clientshared source—a hybrid between the traditional and OSS business logic— can present a new opportunity. Consider a business-to-business (B2B) software vendor whose clients are willing and able to modify source code. The client-shared-source model is particularly applicable when the vendor must customize or extend the product for many clients—for example, in different regions or industry sectors. In this situation, the customizations or extensions are many and varied, yet potentially reusable by other clients not in direct competition. The client-shared-source model is a potential development and business model with practical implications for software architects, developers, and especially development managers. It’s not yet common, but I predict its emergence on the basis of recent OSS and innovation research as well as my own research and experience in telecommunications software. This model can be implemented by vendors of less differentiated products and by consultancies and integrators doing similar projects for different clients, the results of which have been traditionally maintained as separate quasi-products. In the client-shared-source model, the vendor lets clients access the source code—and more—through a common platform. Scott Cook uses the term user contribution system (UCS).1 Satish Nambisan, Priya Nambisan, and Robert Baron urge us to profit from virtual customer environments (VCEs) in product idea generation, development, testing, and support in almost any business domain, not just software.2,3 Both approaches aim to engage clients in product or service development and delivery. We can regard the client-shared-source model, or its supporting infrastructure, as a case of implementing a software-specific UCS or VCE. However, giving clients access to source code has fundamental implications for a firm’s business logic and how it should design, develop, and manage its software.