The Surface Pen is Microsoft's answer to the Apple Pencil. It has been described as an effective stylus, albeit one that could produce more accurate digital writing. A new patent may help improve on this with changes to both the Pen and the screen used.
https://www.notebookcheck.net/New-Microsoft-patent-may-reduce-inadequacies-in-next-gen-Surface-Pen.407171.0.html
Now of course we know that Apple is the "Entity that cannot go wrong" and it is "Always first, always copied and never adopts the ideas of mere mortals" but Apple introduced the "Pencil" as a response to Surface sales success that started destroying iPad numbers and encroaching on the Mac Books, so Surface Pen is not "Microsoft' answer to Apple's Pencil" but rather the opposite - the Pencil was the answer of Apple to Microsoft's Pen.
I know it's hard for you, fanboys.
Oh, and pls note that there are no "fans" to Microsoft. Many people like their products but unlike in the case of Apple fanboys, no sane person roots for Microsoft to dominate its markets and devastate competition. But people clearly see Apple like some kind of tribal honour.
I'm glad this is mentioned in the other comment, but to say that Microsoft is responding to Apple in the stylus department is just bad reporting. That's like saying that Apple also invented the tablet, when windows tried it years prior. Apple made the tablet successful, and Apple put a focus on shading with a stylus like the Surface pen hadn't.
I'm sure that surface pen came out way before apple pencil did. Poor u