From Thelemapedia

The Star Ruby is a ritual written by Aleister Crowley who described it as a “new and more elaborate version of the Banishing Ritual of the Pentagram.” It is still considered to be an official ritual of the A.'.A.'. The Star Ruby will be performed as the opening ceremony of the Babalon Rising festival, and it is recommend that attendees familiarize themselves with this ritual.

From Thelemapedia

Liber Resh vel Helios, by Aleister Crowley, comprises four daily adorations to the Sun, to be performed at dawn, noon, sunset, and midnight. The general object is to focus the conscious mind on the center of our solar system. We will be performing the four stations of Resh daily during the Babalon Rising festival, and recommend that attendees familiarize themselves with this short and powerful Thelemic ritual. 

Local bodies and loose confederations of wandering ritualistic troubadours from all over the US have presented the Gnostic Mass at Babalon Rising. We are proud to host anywhere from 1-3 Gnostic Mass celebrations throughout the course of the festival.

From Thelemapedia

Aleister Crowley wrote The Gnostic Mass—technically called Liber XV or "Book 15"—in 1913 while travelling in Moscow. In many ways it is similar in structure to the Mass of the Roman Catholic Church. However, the comparison ends there, as the Gnostic Mass is a celebration of the principles of Thelema. The ceremony calls for five officers: a priest, a priestess, a deacon, and two acolytes, called “children”. The end of the ritual culminates in the consumation of the eucharist, which is a glass of wine and the host, called a Cake of Light, after which the congregant proclaims “There is no part of me that is not of the gods!”

It is the central rite of Ordo Templi Orientis and it's ecclesiastical arm, Ecclesia Gnostica Catholica. The Gnostic Mass will be performed at the Babalon Rising Festival by [presenter].

As for why Crowley wrote the Gnostic Mass, he explains in Confessions:

While dealing with this subject I may as well outline its scope completely. Human nature demands (in the case of most people) the satisfaction of the religious instinct, and, to very many, this may best be done by ceremonial means. I wished therefore to construct a ritual through which people might enter into ecstasy as they have always done under the influence of appropriate ritual. In recent years, there has been an increasing failure to attain this object, because the established cults shock their intellectual convictions and outrage their common sense. Thus their minds criticize their enthusiasm; they are unable to consummate the union of their individual souls with the universal soul as a bridegroom would be to consummate his marriage if his love were constantly reminded that its assumptions were intellectually absurd.

I resolved that my Ritual should celebrate the sublimity of the operation of universal forces without introducing disputable metaphysical theories. I would neither make nor imply any statement about nature which would not be endorsed by the most materialistic man of science. On the surface this may sound difficult; but in practice I found it perfectly simple to combine the most rigidly rational conceptions of phenomena with the most exalted and enthusiastic celebration of their sublimity.

Crowley published the text of the Gnostic Mass three times: in 1918 in a publication called The International, in 1919 in The Equinox (III:1), and in 1929 in Magick in Theory and Practice. It was privately performed while Crowley was at the Abbey of Thelema, and it's first public performance was March 19, 1933 by Wilfred T. Smith and Regina Kahl in Hollywood, California at the first Agape Lodge. 

Annual Babalon Rising Ritual
The Feast of the Beast celebratory ritual takes place Saturday night at each Babalon Rising Festival. All guests of the festival are invited to join in the Feast of the Beast as is their Will. The purpose of the Feast of the Beast ritual is to usher in the New Aeon and align all participants with the 93 current through the creation of the "Magickal Child". Attendees are encouraged to dress in costume, either as god-forms or as their higher selves/true selves. Scarlet Women, Satyrs, Warriors of Thebes, Maenads, Black-Robed Mages, Skyclad Nymphs, and all and sundry revelers are more than welcome! After the formal portion of this ritual is complete, midnight Resh is proclaimed and an all-night revel begins. Games with prizes will be ongoing. Feasting areas will be available to all assembled. The Feast of Food tent will contain snacks and beverages. Revelers are encouraged to store any alcohol to be consumed Saturday night in this tent, in order to keep glass away from the main fire. Please donate to the Feast of Food tent as you will. The Feast of Flesh tent will contain areas for consensual massage, experimental touch, cuddling, BDSM, and private areas for more intimate contact. Potential hierodules, doms, subs, massage therapists, Heiros Gamos couples, snuggle bunnies, and other individuals interested in pushing the boundaries of physical ecstasy are encouraged to play in this safe, spiritual space. We hope that the Feast of the Beast is an experience that will not only be enjoyable to our guests, but will also assist each of the participants in the realization and achievement of their True Wills. The aims of the Feast of the Beast ritual are summed up in part by Liber LXXVII, included below.

LIBER OZ
Liber LXXVII
"the law of the strong:
this is our law and the joy of the world." AL. II. 2
"Do what thou wilt shall be the whole of the Law." --AL. I. 40
"thou hast no right but to do thy will. Do that, and no other shall
say nay." --AL. I. 42-3
"Every man and every woman is a star." --AL. I. 3
There is no god but man.

1. Man has the right to live by his own law--

to live in the way that he wills to do:

to work as he will:

to play as he will:

to rest as he will:

to die when and how he will.

2. Man has the right to eat what he will:

to drink what he will:

to dwell where he will:

to move as he will on the face of the earth.

3. Man has the right to think what he will:

to speak what he will:

to write what he will:

to draw, paint, carve, etch, mould, build as he will:

to dress as he will.

4. Man has the right to love as he will:--

"take your fill and will of love as ye will,

when, where, and with whom ye will." --AL. I. 51

5. Man has the right to kill those who would thwart these rights.

"the slaves shall serve." --AL. II. 58 "Love is the law, love under will." --AL. I. 57

Aka: "Intro to Babalon Rising Festival;" "Aka: "All First-Timers Should Attend." Babalon Rising gives both fledgling and experienced Magicians the opportunity to explore their own boundaries -- magickally, spiritually, energetically, and sexually. Join Laurelei and other BR-veterans in an open, candid group discussion about respecting and working with both your own boundaries and those of other attendees in a conscious and conscientious Will-based environment.  If you are new the festival, it is HIGHLY recommended that you come to this workshop. (If you are a returning attendee, it is also highly recommended.)