SFZero is a plugin/opensource player of SFZ files. Yes, the naming is extremely confusing.
SFZ V1 was the (I think) first version of the scripting language, and the V2 added some more extensions and flexibility. Then, Aria extensions were added. I think most software players can play SFZ v1 and v2, so there's not much difference really - you can use either set of opcodes as the players recognize both - you can even mix and match. Aria extensions, on the other hand, only works on Sforzando player (?) or Aria player. Aria added more detailed opcodes that most people won't use - However, I do think I did use one Aria opcode for half pedaling, and Garritan CFX uses the ARIA player.
For basic use, SFZ v1 and v2 are really enough .
To give a basic overview of my personal workflow - I make my instruments in Kontakt first because it's a graphical editor, easier to set up/map samples, and easier to tweak curves on a graph rather than numbers in a text editor. Then, when I'm satisfied, or at least close to satisfied, I convert to SFZ. I more or less replicate the numbers that I worked on in Kontakt and code them in the SFZ script. Since I have some piano templates now, its easy to make a piano instrument if you record the right notes in the right order. I just cut it up in Reaper, it autonames the sample files, and the SFZ files automatically render them.
So again, if anyone wants to sample their piano - I can provide a recording workflow and cut up the files into an SFZ instrument pretty easily.
