Microsoft is making good on its plans to open source the .NET framework and has revealed new details on the .NET Core, a fork of .NET that’s been developed to make .NET more approachable to modern-day software developers, the company explained in a blog post. As .NET has matured over the years since its inception, developers have created many variants of the framework to make it function across numerous devices and environments. The new open-source .NET Core essentially removes the need of having multiple versions of .NET, the post explained.
When we originally shipped the .NET Framework in 2002 there was only a single framework. Shortly after, we released the .NET Compact Framework which was a subset of the .NET Framework that fit within the footprint of smaller devices, specifically Windows Mobile. The compact framework was a separate code base from the .NET Framework. It included the entire vertical: a runtime, a framework, and an application model on top.
Since then, we’ve repeated this subsetting exercise many times: Silverlight, Windows Phone and most recently for Windows Store. This yields to fragmentation because the .NET Platform isn’t a single entity but a set of platforms, owned by different teams, and maintained independently.
Of course, there is nothing wrong with offering specialized features in order to cater to a particular need. But it becomes a problem if there is no systematic approach and specialization happens at every layer with little to no regards for corresponding layers in other verticals. The outcome is a set of platforms that only share APIs by the fact that they started off from a common code base. Over time this causes more divergence unless explicit (and expensive) measures are taken to converge APIs.
What is the problem with fragmentation? If you only target a single vertical then there really isn’t any problem. You’re provided with an API set that is optimized for your vertical. The problem arises as soon as you want to target the horizontal, that is multiple verticals. Now you have to reason about the availability of APIs and come up with a way to produce assets that work across the verticals you want to target.
Today it’s extremely common to have applications that span devices: there is virtually always a back end that runs on the web server, there is often an administrative front end that uses the Windows desktop, and a set of mobile applications that are exposed to the consumer, available for multiple devices. Thus, it’s critical to support developers in building components that can span all the .NET verticals.