All of the intelligent upsamplers that we have now—being NVIDIA’s DLSS, AMD’s FSR, and Intel’s XeSS—are fundamentally algorithms at their core, and like any algorithm, they can be tuned and optimized. All three companies continue to do so, which is why game modders and enthusiasts frequently tell folks to update the DLLs for these techniques

Source: Hot Hardware – Intel Releases XeSS 1.2 With Key Upgrades But What Happened To Going Open Source