Born from the high energy physics community at the Large Hadron Collider, hls4ml is an open-source Python package for machine learning inference in FPGAs (Field Programmable Gate Arrays). It creates firmware implementations of machine learning algorithms by translating traditional, open-source machine learning package models into optimized high level synthesis C++ that can then be customized for your use case and implemented on devices such as FPGAs and Application Specific Integrated Circuits (ASICs). Hls4ml can easily scale the implementation of a model to take advantage of the parallel processing capabilities that FPGAs offer, not only allowing for low latency, high throughput designs, but also designs sized to fit on lower cost, resource constrained hardware. Hls4ml also supports generating accelerators with different drivers that build minimal, self-contained implementations which enable control via Python or C/C++ with little extra development or hardware expertise.