The first comprehensive and official Siddur for the Conservative movement is Siddur Sim Shalom. The prayerbook contains prayers for weekdays, Sabbath and the Jewish Holidays, with appropriate additions for Israel Independence Day and Holocaust Memorial Day, all in an easy-to-follow format.
Siddur Sim Shalom also contains services for other events such as Birkat HaMazon (Grace after meals).
The text in Siddur Sim Shalom is nearly the same as that of the Orthodox siddur, but the references to the Temple and animal sacrifices have been changed, so that the text recalls the glory of the ancient Temple service, yet stresses that in our day it is ethical living, following the will of God, and repentance that bring salvation, not animal sacrifice. The extensive introduction in Siddur Sim Shalom presents the themes and structure of the service, and explains the modifications and additions which have been introduced in the Hebrew and English texts, and the rationale behind them.
One of the most significant change in "Siddur Sim Shalom" was the addition of an alternative version of the Amidah, the central prayer in the Jewish liturgy. In the traditional text, the first paragraph refers to the God of the patriarchs - Abraham, Isaac, and Jacob. The alternative version in the new Siddur Sim Shalom includes the names of the matriarchs - Sarah, Rebecca, Rachel, and Leah. Similarly, the matriarchs, as well as the biblical heroines Miriam, Deborah, and Ruth, are included in the ushpizin, a text recited on the holiday of Sukkot.
In 1998, a new edition of Siddur Sim Shalom was published. One of the defining characteristics of the new edition is an increased sensitivity toward gender and feminism.