In the latest version of Houdini Node Bookmarks, the icons will properly work on MaxOSX and Linux platform.
New version of Houdini node bookmarks available, 0.9.9. Fix a bug when data were loaded from hip file data by sessionId
Houdini Node Bookmarks is now available for free, version 0.9.8. Houdini Node Bookmaks For Houdini 16 and 16.5 only.
Houdini Expression Editor Available for free: Houdini Expr Editor