Terminix is a GNOME 3 terminal emulator which utilizes the GNOME header bar thingy (not sure of the technical name). It is actively developed with the most recent commit a day or so ago. HEre is the url for the github: https://github.com/gnunn1/terminix
I know you guys aren't fond of packaging so many programs that do the same thing but, Terminix is a very nice program that is in some ways better than the default GNOME Terminal.
I ( @aldoiljazi ), added some info:
**Is it Open Source:** yes
**Link to source tarball/zip file:** https://github.com/gnunn1/tilix/archive/1.6.1.tar.gz