smsd
· NCATS Fork of Small Molecule Subgraph Detector (SMSD) - A Maximum Common Subgraph (MCS) and substructure generation library for chemoinformatics
Download JD-GUI to open JAR file and explore Java source code file (.class .java)
Click menu "File → Open File..." or just drag-and-drop the JAR file in the JD-GUI window smsd-2.2.3.jar file.
Once you open a JAR file, all the java classes in the JAR file will be displayed.