What are some alternatives?
When comparing Tombstone Engine and JavaFX, you can also consider the following products
Armory3D - Armory 3D is a free and open source game development software developed using Haxe and Kha and made to run inside Blender.
Qt - Powerful, flexible and easy to use, Qt will help you not only meet your tight deadline, but also reduce the maintainable code by an astonishing percentage.
Unity - The multiplatform game creation tools for everyone.
Panda3D - Panda3D is a video game development engine and rendering software. It is developed and maintained by the Carnegie Mellon University Entertainment Technology Center.
PyQt - Riverbank | Software | PyQt | What is PyQt?