Wine 2.21 is a development release coming eleven days after the previous milestone, Wine 2.20, to add a bunch of enhancements, such as indirect draws support in Direct 3D, better serial port detection on GNU/Linux systems, as well as better DPI scaling in the Shell Explorer. It also adds more metafile support in GdiPlus and attempts to fix WoW64 services and calling conventions for ARM hardware. As usual, there are several other bug fixes for various Windows apps and games, and, according to the internal changelog, Wine 2.21 addresses a total of 16 issues.