Learning on Shavuot night

On the first night of Shavuot (this year Tuesday night, May 18, 2010), Jews throughout the world observe the centuries-old custom of conducting an all-night vigil dedicated to Torah learning, and preparation for receiving the Torah anew the next morning. One explanation for this tradition is that the Jewish people did not rise early on the day G‑d gave the Torah, and it was necessary for G‑d Himself to awaken them. To compensate for their behavior, Jews have accepted upon themselves the custom of remaining awake all night.