To design and create files in Sketch, an Apple computer running macOS is required (see the Releases page for current versions supported). This is because the Mac app uses frameworks and technologies that are exclusive to macOS.
However, our Web app is entirely browser-based and works across all major operating systems. This means developers, managers and other stakeholders can view Sketch documents in their browser, inspect elements and even download production-ready assets from designs.
We have also launched an iPhone app that allows you to view documents on the go. You can find out more about this new feature here.
For now, we have no plans to launch the full Sketch platform for Windows, Linux, or other Apple operating systems like iPadOS.