International Music Score Library Project (IMSLP)
IMSLP is the International Music Score Library Project (or Petrucci Music Library) which was started in 2006. The ultimate goal of the IMSLP is to gather all public domain music scores, in addition to the music scores of all contemporary composers (or their estates) who wish to release them to the public free of charge. IMSLP has over 102,959 works, 342,314 scores, 38,827 recordings, 13,705 composers, and 353 performers.