Is Fractal Harness legal in Standard, Modern, and Commander?

Fractal Harness is legal in: Legacy, Vintage, Commander.

Fractal Harness

Q: What type of card is Fractal Harness?

Fractal Harness is an Artifact — Equipment. Its oracle text reads: "When this Equipment enters, create a 0/0 green and blue Fractal creature token. Put X +1/+1 counters on it and attach this Equipment to it. Whenever equipped creature attacks, double the number of +1/+1 counters on it. Equip {2}"