Cygwin's default user interface is the bash shell operating within the mintty terminal emulator.[25] The DLL also implements pseudo terminal (pty) devices, and Cygwin ships with numerous terminal emulators which are based on them, including rxvt/urxvt and xterm. The version of GCC that comes along with Cygwin has many extensions https://devinnpoon.blogars.com/35859866/details-fiction-and-acgwin