This adds the hello-world process in hello-world.c to the platform build, printing "Hello-world" to stdout on startup. The entire platform is built, with uip stack, radio drivers, routing, etc. So it is not usually a simple build! When switching between ipv4 and ipv6 builds on a platform, $make TARGET= clean else the library will contain duplicate or unresolved modules. For example, using a loopback interface with the minimal-net platform: [see http://www.sourceforge.net/apps/mediawiki/contiki/index.php?title=Capturing_loopback_traffic_with_Wireshark] $make TARGET=minimal-net $./hello-world.minimal-net Hello, world IP Address: 10.1.1.1 Subnet Mask: 255.0.0.0 Def. Router: 10.1.1.100 ^C $make TARGET=minimal-net clean $make UIP_CONF_IPV6=1 TARGET=minimal-net $./hello-world.minimal-net Hello, world IPV6 Address: [aaaa::206:98ff:fe00:232] IPV6 Address: [fe80::206:98ff:fe00:232] ^C Note to AVR Raven users: Output goes to UART1, not the LCD. To see it, $make TARGET=avr-raven hello-world.elf Load the .elf in AVR Studio and connect a hapsim terminal to the 1284p simulation.