Performance of LEP and future plans

The performance of LEP (Large Electron Positron colliding beam accelerator) has been steadily improving: 750000 Z/sup 0/ were produced in 1990. Many of the design parameters have been reached separately, showing that the machine behaves basically as expected. In fact, some design parameters have been exceeded ( beta *, emittance ratio) and a significant level of polarization was obtained. An improvement by a factor of up to four in integrated luminosity is still to be expected by overcoming the identifiable limitations: strong synchrobetatron resonances and blow-up of the beam due to the beam-beam effect. Solutions to these problems have been devised and will be tested in a machine study program. The long-term LEP experimental program has been defined by the physics community: a pretzel scheme will be installed to increase the luminosity. It will be followed by the LEP 200 program to increase the energy up to and beyond the W pair threshold.<>