The document discusses high performance GPU computing using Ruby. It summarizes ArrayFire, an open-source library that provides GPU-accelerated operations on multi-dimensional arrays. It also discusses RbCUDA, a Ruby wrapper for Nvidia's CUDA API that allows running CUDA kernels and using CUDA libraries like CuBLAS from Ruby. Benchmark results show ArrayFire and RbCUDA can achieve speedups of over 100,000x compared to non-GPU Ruby libraries for numeric tasks by leveraging the parallel processing power of GPUs. Contributions to the ArrayFire and RbCUDA open source projects are welcomed to further improve high performance GPU computing capabilities in Ruby.