I am involved in the creation of some scientific software which makes use of graphs. At the moment this uses the yFiles graph layout libraries for visualization but I want to look at using a graph database for storing data at the back end too. All of our software is either open source or completely free and this will always be the case. I would like to be able to use embedded Neo4j in my Java application for this purpose but since the code also uses yFiles which is commercial I assume that's not going to work with the GPL3 licence that Neo4j is distributed under? Are there any options for me here or do I need to look at an alternative technology? I have no problem making my own code GPL3 or Apache 2 but clearly thats not going to happen with a commercial library.
Any help would be greatly appreciated.