A recent paper on spiral toolpaths for pocket machining by Mikkel Abrahamsen of Autodesk. It relies heavily on the commercial VRONI voronoi-diagram code (for which there are open-source alternatives such as OpenVoronoi and boost.polygon.voronoi). I haven’t read the paper in detail yet so I don’t know how hard this is to implement. Is there any interest in seeing spiral-pocketing strategies in future open-source CAM libraries?!?
I suppose its always nice to have the choice or option to perform different machining strategies. Am I correcting in thinking that spiral toolpaths are good for chip clearance?
As i understand it, the win with with spiral toolpaths is that you can get consistent chip load.
Yes all the modern “adaptive” pocketing strategies try to maintain roughly constant chip-load, or at least keep the chip-load under a preset maximum value.
A straightforward application of this idea results in “HSM-loops” that I think most have seen: a half-circular like cutting move followed by a rapid repositioning move. The tool might be lifted a lot or just a little (micro-lift) during the rapid re-positioning move.
To minimize cycle-time one obviously wants as little of these retract-reposition-plunge ‘jumps’ as possible. The spiral toolpaths are optimal in this sense, i.e. they keep the tool down for the entire pocket.
Anyway even if we had these fancy strategies available we still don’t have a GPL CAM-gui that could be used to develop/use these 
I really want to get into the @FreeCAD CAM workbench but I just don’t have time at the moment. Hopefully towards the middle of the year I will have more time.
I’ve used PyCAM for a couple of projects. It’s full of quirks, and development has stopped, but version 0.5.1 was usable. It’s the best open-source CAM GUI i’ve ever used.