--- a/.gitmodules
+++ b/.gitmodules
@@ -25,4 +25,7 @@
 [submodule "lib/querypath"]
 	path = lib/querypath
 	url = https://github.com/technosophos/querypath.git
+[submodule "sigma.js"]
+	path = sigma.js
+	url = https://github.com/jacomyal/sigma.js.git
 

--- /dev/null
+++ b/js/bubbletree

--- /dev/null
+++ b/js/flotr2

--- /dev/null
+++ b/js/sigma