  We have conducted a variability survey of the local group galaxy M33 using
g', r', and i' observations from 27 nights spanning 17 months made with the
MegaPrime/MegaCam instrument on the 3.6 m CFHT telescope. We identify more than
36000 variable sources with g',r',i' < 24 out of approximately 2 million point
sources in a one square degree field of view. This increases the number of
known variables in this galaxy by more than a factor of 20. In this paper we
provide a brief description of the data and a general overview of the variable
star population which includes more than 800 candidate variable blue and red
supergiant stars, more than 2000 Cepheids, and more than 19000 long period
variable AGB and RGB stars.
