The pulsed muon facility at ISIS of the Rutherford Appleton Laboratory has been operational since March 1987. It is now fully scheduled for condensed matter research using polarised surface muons, atomic physics with sub-surface muons, and mu-CF experiments requiring negative cloud muons. The design and performance of the present beam are briefly discussed and recent improvements to the facility are described. Essential future upgrades have recently received international support and funding, which will lead to a complete facility comparable in extent to those of the continuous meson factories at PSI and TRIUMPF, but with the unique advantages of the pulsed nature of the source. Such an upgraded facility will provide unprecedented opportunities for muon science at ISIS, unmatched by any other facility until the end of the decade.