What Is .NET Framework?

.NET Framework is Microsoft's original Windows only development platform; version 4.8 is its final release, receiving security patches tied to the Windows lifecycle but no new features, with all active development now happening on modern, cross platform .NET instead.

Applications still built on .NET Framework aren't at risk of a sudden vendor cutoff in the way some legacy platforms are, since 4.8 remains supported indefinitely alongside Windows itself, but they're permanently excluded from newer capabilities like cross platform deployment, containerization, and the performance improvements Microsoft has continued shipping in modern .NET every year since. That gap between the two platforms only widens over time, which makes migration progressively more valuable, if not urgent in the same way an unsupported platform would be.

We assess .NET Framework applications for migration to modern .NET based on how much they'd benefit from cross platform deployment, containerization, and ongoing performance improvements, rather than treating migration as urgent purely on support grounds, since 4.8 itself isn't going away. Where a client's environment already includes newer .NET, we always point migrations at whichever release currently carries long term support, since earlier releases lose support on a rolling basis and shouldn't be treated as a stable landing point. Migration complexity varies considerably depending on which older technologies an application relies on, older components such as WCF or Web Forms tend to be the genuine blockers, so we scope that dependency work carefully upfront rather than assuming every .NET Framework migration follows the same straightforward path.