Currently in Asia, Europe and North America detailed plans for an e+e- Linear Collider with a centre of mass energy up to around 1 TeV are worked out. With such a machine
precision measurements in many fields like top and Higgs production and decay, Supersymmetry or gauge boson selfcouplings are possible.
After a very brief review of the projects the physics with these colliders is discussed in
detail with particular emphasis on the complementarily with LHC.