>>1130868
>steam version compare to the og
The steam version and the free verion on bay12 are both the same game and are on the same version of DF.
With the Steam you are basicaly paying for a premium graphic set and a premium ost, with the added bonus of being able to participate in betas and test branch of more experimental stuff that Toady is adding to DF, like for example, right now there is a beta test for rewriting some of the generator code into Lua files, so that players can fully mod the way that Forgotten Beast, Vampires, Demons, etc generate; plus being able to add new procedural generated creatures of their own. So, all the changes that apply to the steam version also applies to the free one
Now, if you are asking what are the differences between 47.xx (the last DF version before the steam release) and 5x.xx, then the bulk of the changes have been technical under the hood stuff which allowed for a new interface, as well as stuff that used to be done with user mods, like mouse control and being allowed to see what was in multiple z levels bellow the one you are looking at currently.
The biggest and most significant difference so far for fort mode, would be that 5x.xx runs much better overrall (and gen worlds faster too). In terms of content nothing much changed, mostly stuff that was already there got remix or tweeked a bit, like the candy pillars structure that changed a bit, and savage biomes are much more dangerous than what they used to be. Toady is now currently working on fort mode again and he is going to be focusing on sieges for a while, with some of the possible additions being a ranged combat rework, new siege engines, enemies bringing magic users to fuck with your dorfs, as well being able to plan sieges, build siege engines and dig and destroy walls and other obstacles.
Adventure mode saw more content added to it. Most importantly it saw Toady take the first steps towards the fabled Myth and Magic update. Some new dungeons where added where you can find magical weapons/items that allows your adventure to cast some spells (which were already in the game previously but only some creatures could use it), and it also added DF equivalent of a magic healing potion that you can find, and lets your adventurer heal their cracked skull.