I'm not sure this should even be a beta release yet. First the good news. Graphics: OK; close to MSFS (pretty good for freeware, in other words). Sound: Good, but then flight sims aren't the most complex soundtracks on the planet. Stability: takes a long time to load (about 2 minutes) and appears to be the pizza of death, but after the screen changes resolution and aspect ratio a few times it seems to work reasonably well (is the splash screen supposed to tear up like that?). Now the bad. User interface: horrid. Not just the 'ported-from-UNIX-ugly-but-works' style, I mean pull-down menus that don't do anything except tell you to use an XML editor to edit the preference files (hacking is fun, but shouldn't be mandatory). Major settings like screen resolution and controller options seem to be inaccessable from inside the game. Physics: I managed to roll through the terminal building on a take-off run, did an inverted loop (in a 707!) and flew straight through the ground, which then disappeared leaving only a black dot. For me, detecting collisions with ground objects is a major part of the 'simulation' aspect of any flight sim. Its harder to make a comment on the flight models, since my machine (eMac 700MHz, 32MB nVidia, fine according to the limited system specs on the HTML manual pages) couldn't manage more than about 8 fps (guessing, the fps display didn't seem to work), and the poor UI design meant that changing the settings was too much of a chore*. Installation: 'Drag the FlightGear folder to Applications' say the (rather meagre) installation notes: this I tried, and got a permissions error. Fixed with 'Get Info'. The other problems I can forgive as development issues, but this is just plain carelessness. Found no other relevant documentation on the DMG, just some bible quotes, which were absolutely no use under the circumstances (praying DIDN'T help..). Frankly, if this software is actually used by anyone in the groves of academe doing serious research, I'm never flying again! For now, I'd suggest sticking with Warbirds or X-Plane; they may not be open source, but they work.. *I'm one of those old-fasioned people who believe that computers are supposed to make life less complex and more enjoyable, not the other way around.