Any common hardware platform which will support fonts and graphics at a reasonable speed is acceptable. This includes DOS on a 80286, Windows on a 80386, and Mac systems with at least a 68030. In any case, it is now reasonable to expect a 16-bit display, a mouse or similar pointing device, and 4 MB of RAM.
If a DOS program is selected, it is important that it run in graphics mode, as this allows the use of proportional screen fonts. Text mode fonts are much less readable and don't generally support italics, underlining, and other common formatting.