window manager release , used in the Xfce user environment to display windows on the screen, decorate windows, and organize how to move, close, and resize them.
In the new release X11 extension support (X-Resource), which to query the X server for information about the PID of an application running using sandbox isolation mechanisms. XRes support solves the problem of forced termination of hung client processes, whose PID cannot be found through the _NET_WM_PID property, since it reflects the process ID inside the isolated environment, which may differ from the ID in the global namespace.
The new release also a vulnerability that can lead to access to an already freed memory area (use-after-free) and writing data outside the allocated buffer when processing strings with settings. Also, in xfwm4 4.14.3 Additional XError handlers to make it easier to diagnose problems with XConfigureWindow requests.
For some users after updating to version 4.14.3 crashes when trying to run on FreeBSD, apparently due to a new binding to libXres. Also in xfwm4 problem with detecting AMD video cards when enabling the X11 extension XPresent to synchronize output with the vertical blanking pulse (vblank). XPresent was enabled if there was an AMD mask in the card name, while some cards "Radeon" without mentioning the word "AMD" (for example, "Radeon RX 570"). For these cards, the vblank processor based on βglxβ was enabled, which noticeably lags behind in performance.
For example, when using glx, playing 4K video in mpv loads the GPU by 70% in high quality mode and 50% in low quality mode, while the load when using XPresent is reduced to 50% and 30% respectively, which significantly affects power consumption and performance. The problem remains unfixed for now. To force XPresent to be enabled, you can add the /general/vblank_mode setting to xfconf:
xfconf-query -c xfwm4 -p /general/vblank_mode -t string -s βxpresentβ βcreate
Source: opennet.ru