PrusaSlicer

PrusaSlicer began as a Prusa-flavored fork of Slic3r in 2016 and has since outpaced its parent project. It supports FDM, resin SLA (for Prusa SL1/SL1S), and provides excellent defaults for Prusa printers and good profiles for many others — Voron, Creality, generic 0.4mm setups.

Official site: prusa3d.com/prusaslicer.

PrusaSlicer's organic (tree) supports were the first widely-deployed implementation; Bambu and Cura caught up later. Its multi-material extruder support, paint-on supports and seams, adaptive cubic infill, and modifier meshes (for per-region settings) are all reasons advanced users prefer it.

It also reads STEP and 3MF natively, which is helpful when working with CAD output. The settings UI is the most explicit of the major slicers — every parameter has a tooltip explaining what it does and what unit it expects.

OrcaSlicer is a fork of Bambu Studio, which is a fork of PrusaSlicer. SuperSlicer is another PrusaSlicer fork with additional calibration features. The lineage means settings and project files mostly transfer between them, but slicing output can differ subtly.