Facebook's development department has finished a first release candidate for v1 of its PyTorch project – just in time for the first conference dedicated to the Python package. For those not familiar with the tool, its main features are NumPy-like tensor computation with GPU acceleration and a special deep neural network implementation. The preview contains a new set of compiler tools that at runtime rewrite PyTorch models to be more efficient. The just-in-time compiler should also be able to export models that are able to run in a C only runtime. Optimisation is optional and can be done either by tracing native Python code with torch.jit.trace or using a Python subset called Torch Script.