The Liberal Movement began with the work of Lily Montagu and Claude Montefiore during the early twentieth century in Britain. Liberal Judaism, as the name suggests, is a progressive form of Judaism that aims to bring Judaism and modernity together.
To use the movement's own words:
Liberal Judaism is the growing edge of Judaism. It reverences Jewish tradition, and seeks to preserve all that is good in the Judaism of the past. But it lives in the present . . . It is the Judaism of the past in process of becoming the Judaism of the future.
The beliefs of Liberal Jews come from Montefiore’s belief that God did not literally reveal Himself to Moses at Mount Sinai, but rather that God makes His presence felt within each individual (the prophets).
Within Liberal Judaism, people can choose to observe the practices however they wish. In other words, observation of the mitzvot (the 613 commandments by which Jews have to live) is a personal choice.
Liberal Jews pray and worship in a similar manner to those in Reform Judaism. For example, men and women worship together. Also, for Liberal and Reform Jews Shabbat may start at any time on Friday evening.