Complex sentence: GHash.IO is a bitcoin mining pool which allows mining bitcoins with personal hardware or cloud-based mining power; collectively mining bitcoins worth a total exceeding $200 million in its first year.
Split into simpler sentences: GHash.IO is a bitcoin mining pool which allows bitcoins to be mined using personal hardware or cloud-based mining power. The collective value of the bitcoin mined in this pool was over $200 million in its first year.