Pioneer Play is a fork of Pioneer born out of disagreement with Pioneers veteran devs over issues of gameplay. I have now made two attempts to get along with Pioneer devs, both failed rather quickly. I think a lot of the reason is that my vision of Pioneer is different than theirs (see differences below).
To get a copy of Pioneer Play, up to date, right now the only option is to get it from github and compile it yourself:
Pioneer Play is not only a script mod, but actually contains changes in the C++ code. As such, Pioneer and Pioneer Play binaries are not interchangeable.
I will try to provide compiled packages for windows (win32 and x64) in the future as I am a windows user myself (I have several Linux machines at my disposal, but only through remote terminal). But how and when they will be updated, I cannot say.
In Pioneer a new player gets 100 money at the beginning of a new game. The veteran devs refuse to increase start money with the motivation that new players should be forced to do missions to gain starter cash "because they might like it", and because they dont want "boring trading" in Pioneer. For fans of Elite 2 and Frontier First Encounter, the trading in those games meets the definition of "boring trading" and Pioneer devs will actively discourage it from ever being a thing in Pioneer.
Pioneer Play gives you 1000 money and has adjusted commodity prices to enable trading from the very first moments in the game.
Pioneer devs are in many cases more concerned with scientific accuracy than actual gameplay. For example, the HUD will not display your current speed. It will display "the rate of change in distance to your target". I just want to know my speed. Is not much of a difference, its the same number only, in Pioneer its a negative number. In Pioneer Play its a positive number, like you are actually traveling forwards, not backwards.
In Pioneer your fuel is severely limited because "exhaust velocities should be scientifically accurate". That means your fuel will typically run out long before you reach your destination if you accelerate all the way to get there quick. You have to coast with engines off 80% of the way to reach any destination and once you get there, if they dont sell fuel, its game over. Fuel tanks are taking up significant parts of your ship.
In Pioneer Play, fuel calculations have been changed to allow multiple full acceleration trips before needing refuelling. So that you are free to explore, or make mistakes, without having to restart your game all the time.
Pioneer devs discourage adding new text because they want to "spare their translators". This means a lot of explanations and "ambience" is left out. With Pioneer Play, I (Im still alone on this project), will try to add text as descriptions or flavor to try to bring more life and variation into the gameplay. This might make Pioneer Play into an english only game, but I cant do much about that...
There is one more fork of Pioneer called Pioneer Scout Plus, but the last update was in december 2016. Still might be worth a try if neither the main Pioneer or Pioneer Play suits your playstyle.https://sourceforge.net/projects/pioneersp/