To install the software on your OS directly you can follow the following guidelines (Links are for Ubuntu OS, other tutorial for other OS can also be found) :
Contiki OS https://github.com/contiki-os/contiki/wiki/Setup-contiki-toolchain-in-ubuntu-13.04
GNS3 https://community.gns3.com/thread/5471
Mininet http://sdn-lab.com/2014/12/31/setting-up-mininet-2-2-on-ubuntu-12-04-and-14-04/