MuseScore is a free music notation and composition software available for Windows, Mac, and Linux. 

It allows for fast and easy note entry on a virtual note sheet. It has an integrated sequencer to allow for immediate playback of the score. MuseScore can import and export MusicXML and standard Midi files.

MuseScore is available in more than 40 languages and is rapidly becoming the leading free music notation software and often praised as a cost effective alternative for expensive software.

MuseScore features a direct connection with the sheet music sharing site MuseScore.com via the MuseScore Connect panel. This gives users direct access to thousands pieces of sheet music shared by the community.

MuseScore.com also invites users who share sheet music frequently to upgrade to MuseScore.com PRO, which features more onlinemixing tools and no ads. It also allows users to upload and share more sheet music, since the free version offers space for at most five scores stored online. It must be noted that while MuseScore.com has a paid subscription model, the actual software, MuseScore, remains completely free and open source software.

MuseScore

Windows

Linux

PortableApps.com

MuseScore is a free music notation and composition software available for Linux, Windows and Mac. .

Write music quickly and easily
Sibelius features an intuitive task-based interface that leads you through the entire score creation process, so you can jump right in and start composing music immediately. Enter notes from the onscreen notation, keyboard, or fretboard windows, or from your MIDI or computer keyboard. Sibelius takes care of all note layout, orientation, and rest details for you.

Build up your composition
With support for up to 16 instrument parts (staves), you can create rich, multilayered compositions. But it’s not just about notes. Add chord symbols and guitar chord diagrams by simply playing a chord on a MIDI device or typing suffix elements. Turn guitar tab into notation and back again. And easily add lyrics, titles, text, and graphics to round out your score.

Create beautiful scores fast
Spend more time writing music instead of fixing it. As you write, Magnetic Layout automatically gives everything just the right amount of space and avoids collisions to produce beautiful results, cutting writing time in half. And Dynamic Parts can automatically create and update separate instrumental parts whenever you change your score.

Turn music into scores
Sibelius comes with two companion applications that enable you to turn recorded, performed, printed, and handwritten music into notation. With AudioScore Lite, you can input notes by singing or playing a monophonic instrument through a microphone. With PhotoScore &amp; NotateMe Lite, you can turn printed, PDF, and JPEG sheet music into editable scores—and even handwrite music.

Hear your music in stunning detail
With the included 10 GB sound library of high-quality sampled instruments, you can play back compositions to hear how it would sound with full instrumentation. The Espressivo feature adds a more humanistic feel, so your score sounds the way you intended it to be heard. You can also use VST and AU virtual instruments and effects.

Sibelius

Sibelius is a scorewriter program, created by Sibelius Software (now part of Avid Technology) for Microsoft Windows, OS X, and historically RISC OS.

    Next-generation 64-bit scoring software for OS X and Windows, designed by musicians for musicians
    Beautiful engraved output with unrivaled attention to detail
    Flexible note input and powerful editing, including ability to insert and change duration of existing notes
    Streamlined, single window interface puts every tool at your fingertips

    Powerful score management features to handle multiple independent pieces of music within the same project
    Unlimited number of staves and movements, sections, or pieces within the same project
    Easily create layouts for full scores, conductor scores and instrumental parts with independent page size, staff size and system layout

Dorico

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.

Finale is proprietary scorewriting software developed by MakeMusic, Inc.  It displays music primarily in music notation and allows for multiple tracks and very specific tweaking of instrument sounds for each track.

Apps with 'Music XML Support' feature

MuseScore

Sibelius

Dorico

Finale