TNTversion 1.6, with a graphical interface forMacOSand Linux, including new routines in parallel

A new graphical user interface (GUI) for the parsimony program TNT is presented that works under the Linux and Mac operating systems, as well as the Cygwin environment (which runs under Windows). The new interface is based on the GIMP Tool Kit, GTK (version 3). Formerly, only Windows versions of TNT had a GUI. The new interface improves upon the existing Windows GUI in several respects. These changes, together with several additions to the program since the publication of version 1.5, warrant a change in minor version, thus moving from version 1.5 to 1.6. Among the most notable improvements are the possibility to access graphical user dialogs by means of simple commands, to easily save trees in SVG format ("Scalable Vector Graphics") directly from any tree-diagram being displayed, and to manage analyses in parallel (using multiple processors, by means of the PVM system or "Parallel Virtual Machine"), as well as a generally more stable and consistent behaviour. As the binaries for the new version are compiled as native 64-bit applications, this removes the limitations for accessing large amounts of memory in the previous GUI Windows interface (which is a 32-bit application).