+ * ccache http://ccache.samba.org/ to improve recompilation
+ * libgc-dev http://www.hpl.hp.com/personal/Hans_Boehm/gc/
+ * graphviz http://www.graphviz.org/ to enable graphes with the nitdoc tool
+ * libunwind http://nongnu.org/libunwind
+ * gperf http://gnu.org/software/gperf to enable mapping from C to Nit function names in a stack trace