Different technologies are required to run Windows applications. The best known in the Linux world is WINE, but it also uses other software, such as Mono motor. It is what makes programs that depend on Microsoft's .NET (framework) work, and until a few hours ago it was managed by the company that also develops the most used desktop operating system in the world. This week he decided to let go of his burden, or trust in others, as you prefer, and he gave it up.
The company that will take over from now on is WineHQ, who also develops WINE. This has been announced in page of the Mono engine, where Microsoft describes it as "a pioneer for the .NET platform on many operating systems«. New repositories are now available, and Microsoft will keep most of the ones open until today. The binaries will continue to be available for at least 4 more years.
The future of the Mono engine
Once upon a time, the Mono engine was also used in Linux applications, but developers have ended up opting, for the most part, for other software. The important thing now is that compatibility with .NET software. Microsoft slowed down development of Mono and its last major update was in 2019.
Now that Mono will be maintained by WineHQ and the patent is not a problem, progress will be possible more quickly, which will surely will further improve compatibility of Windows applications on Linux — and other operating systems — under WINE.
There are many popular applications that use .NET, such as Visual Studio, Paint.NET, Skype or Microsoft Office. If support for Mono is improved, and it will be, applications like these and many others will run better on Linux, although Skype or Whatsapp offers a native version in snap format. The Visual Studio mentioned is not Code, but the more powerful older brother that also offers paid versions.
In short, better support for Windows applications is expected on other systems, including the Linux that we like so much. As long as they use .NET.