Regarding performance: "Note that current raw performance of Java on Truffle isn’t representative of what it will be capable of in the near future. The peak performance is several times lower than running the same code in the usual JIT mode. The warmup also hasn’t been optimized yet. We focused in this initial release entirely on the functionality, compatibility, and making Java on Truffle open source available for a broader community. ... Expect performance, both warmup and peak performance to increase rapidly in each of our upcoming 21.x releases."

> Running HelloWorld on three nested layers of Espresso takes ~15 minutes.

It’s like how time works in “Inception”.