If you’ve been reading about modular instruments, or speaking with one of several vendors that offer AXIe-compatible products, you may have come across the term “AXIe”. What is it? Where is it used? How is it different, or similar, to other instrument standards? How does it compare to PXI? If so, you’ve come to the right place. These are the questions I aim to answer in this introduction to AXIe.