psignifit used to be called "psychofit"...
... which seemed like the obvious name for software that fits psychometric functions. Clearly it was too obvious, because it turned out that others had used it before, to describe some psychological profiling techniques used in criminal investigations, as well as for psychophysical software. David Panek and J. C. Stevens released psycho-acoustical software called "psychofit" in 1965 and 1969, and Lewis O. Harvey also has a psychometric-function fitting package of this name (see below).
So as not to cause confusion or tread on any toes, I thought it a good idea to think up a new name, and the move to bootstrap-software.org seemed like a good time to do it. Admittedly psignifit sounds a little too much like it was dreamt up in the marketing department of an American corporation, but it's beginning to grow on me - it has the advantage of emphasizing the importance of significance testing in psychometric-function fitting, which is the central idea of the project.
Any of our publications written before March 2002 still refer to the software as "psychofit", so in order to clear up any confusion, the difference is as follows:
psychofit (now known as "psignifit") by Jeremy Hill
This is the software available here on bootstrap-software.org, and which is referred to in the following papers:
PsychoFit by Lewis O. Harvey
Lewis Harvey's PsychoFit is not connected with this website. It is available at http://psych.colorado.edu/~lharvey/, and is described in the following papers: