Nereid, the third largest of Neptune’s moons (mag. 18.69) and Minor Planet Christophe

[theskyhound]

I think a distinction needs to be made between simple plate solving, for which the algorithm used in astrometry.net is still absolutely king, and astrometric plate solving. These are two different things. I presumed from the context that people were asking about a general plate solution rather than to do astrometry. SkyTools is primarily planning software. The ability to match your images to the data is useful, but it is not going to become a full astrometry engine. There is existing software for that, and if it writes the plate solution in a standard way to FITS, then SkyTools can use it.

I'm not sure about ASTAP, but all of the other astrometric engines use the astrometry.net code to calculate the "rough" position as a starting point because it has the unique ability to match any set of stars at any scale.