image/svg+xml PUBsfasdfasdf IPython Kernel REQ XREP PUB - Kernel raw_input - Requests to kernel - Kernel output broadcast - Request/Reply direction Front-end Kernel Proxy REP SUB XREQ Front-end Kernel Proxy SUB XREQ Front-end Kernel Proxy SUB XREQ Q W E R T Y U I O P A S D F G H J K L Z X C V B N M 1 2 3 4 5 6 7 8 9 0 ENTER Q W E R T Y U I O P A S D F G H J K L Z X C V B N M 1 2 3 4 5 6 7 8 9 0 ENTER Q W E R T Y U I O P A S D F G H J K L Z X C V B N M 1 2 3 4 5 6 7 8 9 0 ENTER