Having a list of supported browsers is fine. All modern browsers are supposed to implement the same web standards, but they all have a different set of supporte

Having a list of supported browsers is fine. All modern browsers are supposed to implement the same web standards, but they all have a different set of supported features and subtle rendering and layout bugs. Sniffing the User-Agent string to detect the browser is a small evil, but it's sometimes necessary. Having a list of supported operating-systems is totally different. For a web app, this is almost never okay. The popular cross-platform browsers (Chrom{e,ium} and Firefox) are excellent examples of well designed cross-platform software. They both abstract the underlying platform and implement the layout engine in platform-independent code. It's very rare to find a rendering bug in these browsers that only affects a single platform. So, what I don't understand is why OneDrive is sending different code to Firefox on Linux and Firefox on Windows, and why are the support team being instructed to dismiss bug reports from Linux users when they are using a browser that would be supported on Windows? It's hard not to attribute this to malice. Even perpetuating the idea that it's not possible to write truly cross-platform software or that web apps have compatibility with specific operating systems works in Microsoft's favour, since they sell the most popular desktop operating system.