Oolite and memory lane
One of the things that was most appealing about my first computer, besides the fact that my mate Mark had one, was the fact that the BBC 'B' was the home of Elite, David Braben & Ian Bell's mammoth space-trading game.
I spent many, many, hours playing. There was a charity push at school once, probably for something like comic relief, and I managed to somehow get the school to allow me to do a sponsored-playing-Elite, where people payed money to charity, and I played Elite, all day (on a school day!). I used one of the BBC Master computers, in one of the French classrooms (which was a portakabin). I think I was sponsored on a per-kill basis. Looking back, it seems astonishing that I was allowed to do that, and that people actually sponsored me to do it.
In the end, the only thing that prevented me from becoming Elite (there was nothing as mundane as an 'end' to the game) the game was that the disc was lost. I can't remember is whether it was lost, as in lost to enemy action (another friend, who shall remain nameless, who borrowed either the Elite or Exile disc and somehow managed to reformat it), or lost as in unable to locate it, either way my Elite career was postponed at Dangerous for several years, until the arrival in my house of an Acorn A3010 RiscOS machine, and the RiscOS port of Elite (usually called ArcElite), still considered by many to be the definitive version of the game.
I lost many more hours to this new version, and enjoyed it enormously, although it never quite clicked the way the original had, I think mainly because I never quite made the jump to mouse control, which I think made combat much, much, harder for me (the enemies certainly didn't behave the way that they used to, and most of my old tactics just weren't effective), and my space-based trading and combat heart went to Gordon Key's magisterial Black Angel (but that's another story).
And then, Robin at work innocently asked if I'd seen Oolite, and then he explained what it was: A Creative Commons licensed from-scratch re-engineering of the original Elite, orginally for Mac OS X but now ported (using GNUStep) to Linux and Windows. I downloaded it, dropped the provided Acornsoft Elite control keymap in and hey presto, my Powerbook was a Cobra Mk III, and I was twelve again.
In fact, I'm currently flying what I think is exactly the same trade route I used to run when I just started out (Isinor - Ensoreus, if you're interested), in 1989. And, you know, it still rocks. I've even managed to relearn my old trick, the full-speed manual dock (although the new navigation buoys mean that my old fly-past alignment technique isn't needed any more). It's amazing how compulsive the original gameplay still is, and it's amazing that my muscle memory let me pick up almost where I left off, still a fluent pilot nearly 17 years after I started, and nearly 10 years after I last flew.
It's still remarkable to think that this game originally came out in 1984, more than ten years before the original GTA, and was the original sandbox. The disc version of the BBC game had only two 'missions', whose completion (or lack thereof) affected the longer game not at all: you didn't win, you didn't lose, you just gained a new toy or the galaxy's meaningless gratitude. You could happily play for a very long time and never trigger either of them and that was that. The game never ended, not even when you gained the rank of Elite. The fullness of the universe was a trick (the galaxies, with stars and names and the little bit of blurb were generated pseudo-randomly from a 6 byte seed to save memory (see answer 13 on this David Braben) page), their consistency thanks to a predictable algorithm), a gauze hung over the core mechanics of trade and combat. The galaxies were brought to life by the power of suggestion and a willing suspension of disbelief, a sandbox game made from vectors and 6 bytes of data.
Oolite makes use of the idea which made ArcElite such a wonderful update: you are not the centre of the universe. Stuff happens around you as ships come and go, fight among themselves, ask for help and generally get on with things. These are more suggestions, reinforcing the player's immersion in the sandbox and allowing them to will the universe to richer life. The nicer graphics are almost irrelevant to Oolite's appeal, it's the convoys, the maydays, and the 'people' getting on with things that do it for me.