Howl is a C ABI embeddable terminal stack.
The product boundary is the ABI: hosts embed PTY, VT, and render libraries through public C headers, while each host owns platform UX, event loops, wake policy, presentation cadence, runtime orchestration, and backend resources.
howl-pty: PTY-backed child transport, lifecycle, resize, input/output, wait/kick, and control signals.howl-vt: terminal parser/state, visible-surface truth, selection, input encoding, and host-facing protocol consequences.howl-render: backend-agnostic render contracts, geometry, text shaping, prepared surfaces, and submit/retire state.howl-linux-host: reference Linux desktop host using SDL/OpenGL.