The performance of the LHC depends critically on the low-triplets, located on either side of the interaction points. Each triplet consists of four superconducting quadrupole magnets, which must operate reliably at up to 215 T/m, sustain high heat loads and have an excellent field quality. A collaboration between CERN, Fermilab and KEK was set up in 1996 to design and build the triplet systems, and after nine years of joint effort the production will be completed in 2005. We retrace the main events of the project and present the performance of the low-quadrupoles built by KEK and Fermilab and of other elements of the triplet. The assembly of the first triplet at CERN and plans for tunnel installation and commissioning in the LHC are also reported.