Riposte

Riposte is a trace-driven compiler and parallel virtual machine for R. It records the vector operations an R program performs at runtime, fuses them into compiled traces, and executes those traces in parallel — reaching performance competitive with hand-written C for many vector workloads while running unmodified R code.

The work explored how far a dynamic, vector-oriented language can be pushed by specializing on the shapes and lengths that actually appear at runtime, rather than on static type information.