How can I batch-convert Sony ARW files to JPEGs with results similar to the camera’s JPEGs?

For the closest match to Sony’s in-camera JPEGs, the best choice is Sony’s own software, Imaging Edge. Camera makers’ RAW software often applies the in-camera settings recorded at capture, so it’s the most likely to resemble the camera’s automatic JPEG output.

If you need Linux-native options, RawTherapee, darktable, and UFRaw can all batch-convert ARW files and can be scripted from the command line, but they may not match Sony’s JPEG rendering as closely as Sony’s own software. If needed, you could try running Imaging Edge under WINE.

One community report found Imaging Edge gave very good results and processed large batches reasonably quickly. FastStone Image Viewer was also reported to produce nearly indistinguishable results in one comparison, though with larger JPEG files.

So, in order of “closest to camera JPEG”: start with Imaging Edge, then try FastStone (Windows), and use RawTherapee/darktable/UFRaw if you need Linux tools and are okay with slightly different rendering.