Future wireless network architectures will transform into multi-vendor, highly disaggregated distributed systems with open interfaces operating on virtualized computing and networking environments. Emerging 5G and Open RAN architectures are the first generation of standards to embrace this transformation fully. Growing demands and emerging use cases for future wireless networks will require higher spectral efficiency, exploration of new frequency bands, increased energy efficiency, and support for new spectrum-sharing approaches. The availability of robust open-source software (OSS) will catalyze the evolution toward disaggregated and virtualized network architectures. It will fuel innovation and competition in future wireless technology and spectrum utilization. While many disjointed efforts are developing OSS for future wireless systems and supporting virtualization platforms, there is often significant diversity in the maturity of such implementations regarding alignment to standards, feature support, interoperability of distinct components, security and resilience mechanisms, and system scalability and performance. Moreover, the lack of transparency about these issues poses significant challenges to researchers and network operators in adopting current OSS implementations as the basis for future development…