Yes ASRock is a subsidiary of Asus. Founded by some Asus co-founder.
Yes It has decent quality for it's price. Nearly five of my friends own this brand and they are running their rigs without any problem. It is recommend for building low budget PCs. And that's not to say that it is cheap. And, i must admit... they are feature rich too. You can get a mobo with wifi for just 2.8k or something(IIRC).. which wasn't there in my 6k intel board