Yes Oblong is correct... MLB Advanced Media took over control of all MLB sites in 2001, which lead to this site eventually. They also run MiLB sites like was mentioned.
However, I did not know that they (MLBAM) also run the NHL sites and other properties... Interesting.
From Wikipedia: (https://en.wikipedia.org/wiki/MLB_Advanced_Media)
"MLBAM also runs and/or owns the official web sites of the National Hockey League and Minor League Baseball, YES Network (the television broadcaster of the New York Yankees), SportsNet New York (the television broadcaster of the New York Mets). It has also provided the backend infrastructure for WWE Network, WatchESPN, ESPN3, HBO Now, and PGA Tour Live."