[fcjr]

For firefox xpi files its that simple, for chrome crx files, you have to strip the crx header from the file before it can be opened as a traditional zip file (so read the header to find its length then strip it). But yeah it's fairly simple. This was mostly created as a simple tool for the product team at my old company to extract crx files so they could side load development builds without them having to install anything or be aware of the fact that these are essentially just signed zip files (much like Apples xip format).