>>392524841. Smogon is a popular "battle institution" (i.e a set of rules someone put online and people adopted). Pokemon are ranked by viability (Reshiram, Arcues, fug are in another level to Linoone and Ampharos) and usage (High usage to the top, low usage at the bottom). Smogon is not TPCI official, and anyone who refers to Smogon as "the official way to play Pokemon" has thier head up their ass.
2. Pokemon Showdown is a free "Competitive Battle Simulator". Not owned by TPCI. Every Pokemon's BST, moveset, abilities, and items are available. IVs, EVs, and Natures can be freely customized, so it's a quick alternative to breeding.
I reiterate: POKEMON SHOWDOWN IS NOT OFFICIAL. No idea why TPCI has yet to kill it. Could be popularity, could be Smogon, but it's free (until zarle starts charging money for it)