  After 12 years of glorious data taking LEP has been shut down. During the
past two years an incredible effort has been devoted to get more accurate
predictions and estimates of the related theoretical uncertainties. Many of the
theoretical questions driven by LEP are also relevant at the LC, where
predictions will be needed with even higher accuracy. This is particularly true
for 4-fermion Physics. In this contribution, I review some of the most
important theoretical achievements at LEP in understanding W and Z pair
production, 4-fermion + 1 visible photon signatures and in solving problems
related with gauge invariance. Issues on single W Physics are covered
elsewhere.
  Part of the presented work is in progress, the final LEP2 analysis still
being under way.
