The Pledge of Kwan Yin
 

Many are familiar with the graceful statues of Kwan-Yin, bodhisattva of compassion. Like all such selfless beings, long, long ago she vowed to dedicate all her lifetimes to helping others spiritually.

Her Pledge is here given and the late Raghavan Iyer plumbs some of the profound depths found in this vow.

http://theosophytrust.org/tlodocs/PledgeKY.htm

Is Kwan Yin prayed by the buddhist or taoist?

From what I know, Kwan Yin should be prayed by buddhist

it is unsure if it came from Buddhist or Taoists, both pray to her.

Anyone can pray to her.

Kwan Yin is a Buddhist bodhisattva, but anyone can pray to her, because bodhisattvas help everyone.

I already posted this on my space thread but ill post this here too.
from wiki:




Kuan-Yin means "one who hears the cries of the world." Her five major virtues are mercy, modesty, courage, justice, and wisdom. She is also known as the Goddess of Compassion.
In Buddhist tradition she is a bodhisattva. This is a soul who is fully realized and no longer needs to reincarnate, but chooses to do so in order to enlighten others. It is said that when Kuan-Yin was ascending into spirit she heard the cries of suffering humans and chose to re-enter physical existence.



It is possible that Guanshi'yin (kwan yin) originated as a Taoist deity, the Queen Mother of the West. With the introduction of Mahayana Buddhism to China in around the 4th to 5th centuries, Taoism and Buddhism became religious rivals in China. The Buddhist tactic was to change, and even supplant, indigenous Taoist deities in favor of Buddhist deities. Over the centuries, this trend has had the effect that it is now virtually impossible to determine Guanshi'yin's true origin.wiki

This section of the Lotus Sutra gives some of the benefits that Kuan Yin can bestow:

http://www.fodian.net/world/0262_25.html

skull, who is that in your avatar?

“…….never will I enter into final peace alone……”

This is a very powerful excerpt from her vow, IMO