GNU LilyPond is a computer program for music engraving. One of LilyPonds major goals is to produce scores that are engraved with traditional layout rules, reflecting the era when scores were engraved by hand.
LilyPond vs MuseScore opinions
Lilypond provides everything a graphical interface such as Musescore could provide and more. The fact it uses a markup language to export a pdf. MusicXMl, midi, or svg from makes it extremely accessible. The learning curve is a bit harsher, but it pays off so much.
Sibelius is a scorewriter program, created by Sibelius Software (now part of Avid Technology) for Microsoft Windows, OS X, and historically RISC OS.
Impro-Visor (short for “Improvisation Advisor”) is a music notation program designed to help jazz musicians compose and hear solos similar to ones that might be improvised. The objective is to improve understanding of solo construction and tune chord changes.
GNU Denemo is a music notation editor that lets you rapidly enter notation for typesetting via the LilyPond music engraver. You can compose, transcribe, arrange, listen to the music and much more.
Dorico redefines the gold standard in scoring software. Its musical intelligence is like having an expert assistant by your side, while its intuitive workflows help you focus on each aspect of score preparation.
Aria Maestosa is an open-source (GPL) midi tracker/editor. It lets you compose, edit and play midi files with a few clicks in a user-friendly interface offering keyboard, guitar, drum and controller views.