It extends Java, building in fairly comprehensive language interoperability. Honestly, it's an amazing feature...and also the perfect trap. If you build your co

It extends Java, building in fairly comprehensive language interoperability. Honestly, it's an amazing feature...and also the perfect trap. If you build your code taking advantage of it, you lose compatibility with standard JVMs and you give Oracle leverage over you. And the moment they think they have you, they'll do an about face on their licensing and start charging you for it.