I used a Blit successor (AT&T 5620 nee DMD) in the 1985ish time frame. It was attached to an AT&T 3B2 host running SVr3 and later SVr4. It was a very cool, minimal, useful and very Unixy way of doing things. The "window manager" software was called "Layers", and allowed a lot of application processing to happen on the terminal. Layers windows behaved (mostly) just like ttys multiplexed back to the host. There was a pretty decent cross development environment for creating little apps, including a C compiler and debugger. There were the normal doodads like a graphical clock, drawing program (pic?), calculator. There was also a pretty neat mouse-enables editor called 'jim' and I seem to remember a sort of troff previewer. Pretty much the coolest thing I'd ever used up until I got a Sun 3/160 in '86 or so running SunOS 3.x and OpenWindows. Game over.