In late 2014, Microsoft announced the open-sourcing of .NET, leading to a significant shift towards open-source projects and enabling the running of C# and .NET code on Linux environments through containers like Docker. Despite the historical limitations of older .NET versions, such as .NET 4.5.x being tied to Windows, the introduction of .NET Core has facilitated C# applications to run natively on Linux with a smaller API surface. This transition has been supported by projects like Mono, an open-source implementation of .NET that allows cross-platform compatibility, albeit requiring codebase adjustments. The push towards containerization, using Docker for both Mono and .NET Core apps, showcases a shift towards microservices architecture, allowing developers to leverage new technologies like NodeJS while maintaining the robust features of C#, such as async/await and strong typing. This evolution not only supports developers in expanding their technological horizons but also enhances the competitive edge of .NET in the Linux-dominated web stack landscape.