This is a direct continuation of @britzl 's Dear ImGUI extension for Defold.
At some point I just added ImNodes inside and tried to use it to create some Node Graphs, but never actually finished, so I decided to share it nevertheless as it’s already a good starting point and someone we could all together work on. It’s fully open-source, MIT like all involved libraries.
The project added ImNodes files to the extension and some most fundamental (not all) ImNodes functions are added - you can find it in extension_imgui.cpp in “Node Editor” section.
The project includes example script - build it and check out what’s working and what not 
The example uses some Lua modules to simplify usage of ImGUI and ImNodes.
At some point I thought it was some great approach, but it’s actually really hard to create such project. It might be though a very good base for some visual programming or at least some useful gamedev tool! 
Here’s the link: