SaddleDrop is a software created by K. Papadantonakis working with J. H. Hubbard, J. Smillie, and E. Bedford. SaddleDrop is able to draw pictures of Hénon parameter space, and provided the first glimpses of this. It was used by many to study parameter space, and Lipa used it to formulate his monodromy conjectures.
SaddleDrop was written in a hardware specific way, using the PowerPC processors in Macintosh machines. In 2005, Apple began a transition away from this architecture to Intel processors and as such SaddleDrop eventually became unusable on modern computers. Thus, an important resource was lost. It is possible, but now difficult (and expensive), to find machines capable of running SaddleDrop. However there is a way around this. One can use the software SheepShaver to emulate Mac OS 9 on both Windows and Mac OS X. This is a rather intimidating process to undertake from scratch.
Edward Mendelson, the Lionel Trilling Professor in the Humanities at Columbia University, has created packages for Mac OS X and Windows requiring no knowledge of SheepShaver. One simply downloads the correct .zip file for their operating system and expands it. This will give a Mac OS 9 application. When opened, one sees a Mac OS 9 desktop which can be used in the usual way.
Now to get SaddleDrop (FractalAsmn works the same way) working on this, download the (stuffed and binhexed) files from here. Drag these files on top of the Mac OS 9 desktop icon to add them to the emulated desktop. Now clicking on these will expand them using the inbuilt StuffIt program. One will now see a folder containing the SaddleDrop program. This should be left in the folder and not moved out or this may cause problems.
You can now open SaddleDrop and use it. The program includes some information on how to create parameter space pictures. Below shows a $c$-plane picture with Jacobian parameter $0.05i$.