  The Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) represents the most
powerful weak lensing survey carried out to date. The CFHTLenS
(Canada-France-Hawaii Telescope Lensing Survey) team was formed in 2008 to
analyse the data from the CFHTLS focussing on a rigorous treatment of
systematic effects in shape measurements and photometric redshifts. Here we
review the technical challenges that we faced in analysing these data and their
solutions which set the current standard for weak lensing analyses. We also
present some science highlights that were made possible by this effort
including cosmic shear tomography, tests for modified gravity models, and the
mapping of dark matter structures over unprecedentedly large scales. An outlook
is given on current and future surveys that are analysed with the tools
prepared for CFHTLenS. CFHTLenS represents the first and only weak lensing data
set that has been made publicly available so far. We encourage other surveys to
follow this example.
