From the Readme file:
There are four versions of X-Plane on this CD:
- CLASSIC for Macintosh
- 5.54 for Macintosh
- CLASSIC for Windows
- 5.54 for Windows
X-Plane Classic will almost certainly work on your machine regardless of what type of machine you have, and will give great frame rates (fluid feeling of flight) as well. The drawback is that the graphics are sort of plain.
X-Plane 5.54, on the other hand, has outstanding graphics, but the drawback is that you must have a 3-D accelerator video card that has OpenGL drivers to run that version.
English 
Comments and reviews
this is soooo cool especially how i can make my own airplane. i didnt know it is still updtable!
How to make it non demo version ?
What about the earlier games in the series?
Was there ever a No-CD for 'Classic version' of the game?
This runs really well on Windows 10 without any fiddling about at all. Very playable. You can actually get updates for this (5.6, 5.99) from the x-plane site.
No comment nor review for this game at the moment.