Incorporating pretty much the same improvements that the Linux Mint devs implemented in the final releases of the Cinnamon and MATE editions of Linux Mint 18.3 “Sylvia” earlier this week, today’s KDE and Xfce flavors are based on Ubuntu 16.04.3 LTS (Xenial Xerus) and powered by the Linux 4.10 kernel. While Linux Mint 18.3 “Sylvia” Xfce Beta edition ships with the latest Xfce 4.12 desktop environment, the Linux Mint 18.3 “Sylvia” KDE Beta edition comes with the long-term supported KDE Plasma 5.8 desktop environment, which will receive upstream support up until April 10, 2018, when the KDE Plasma 5.8.9 maintenance update is out.