Install

The module and the nwc2musicxml command are one CPAN distribution. Perl 5.36 or newer is the only thing that has to be there beforehand.

From CPAN

cpanm Music::NWC2MusicXML

cpanm installs the dependencies below as it goes. Without App::cpanminus, cpan Music::NWC2MusicXML does the same job, and cpanm --installdeps . in a checkout installs exactly the versions that checkout declares.

From a checkout

git clone https://github.com/nigelhorne/NWC2MusicXML.git
cd NWC2MusicXML
perl Makefile.PL
make
make test
make install

make test runs the full suite. The part worth knowing about is t/40-input.t: it converts every .nwc file in t/input/ and compares the result byte for byte with the golden .musicxml file committed beside it. A change that alters the output of an existing score therefore fails the suite rather than passing quietly.

What it needs

Requirement	Why
Perl 5.36 or newer	The minimum is declared in `Makefile.PL` and is not a guess: the modules are written for that version's semantics.
`Compress::Zlib`	The NWC container is a zlib stream. This is the only dependency that is not pure Perl, and it has shipped with Perl for years.
`Object::Configure`	Lets a program set converter defaults once, at class level, instead of passing them to every `new`.
`Params::Get`, `Params::Validate::Strict` (0.39+)	Argument checking for the public methods, so a misspelt parameter is rejected instead of ignored.
`Readonly`	The parser's dispatch table and the pitch, clef and tempo maps are read-only constants built once at load.
`Carp`, `File::*`, `Getopt::Long`, `Pod::Usage`	Core modules: errors, file handling, and the command line.

Nothing else is required. There is no NoteWorthy Composer, no Java and no libxml2 involved: the MusicXML is written directly rather than through an XML library, so the converter runs anywhere Perl does, including on a server with no desktop software at all.

Check it works

nwc2musicxml --version
nwc2musicxml --help

The help text is the command's manual page as well: perldoc nwc2musicxml prints the same thing, and perldoc Music::NWC2MusicXML documents the Perl API. If nwc2musicxml is not found, the installation put it somewhere your PATH does not look — perl -V:installbin says where.

What gets installed

Path	Purpose
`bin/nwc2musicxml`	The command-line interface.
`Music::NWC2MusicXML`	The facade: `convert`, `batch_convert`, `diagnostics`.
`Music::NWC2MusicXML::NWC`	Binary container decoder: signature check, zlib inflation, NWCTXT text.
`Music::NWC2MusicXML::Parser`	NWCTXT text to a score of staves and events.
`Music::NWC2MusicXML::Score`, `::Staff`, `::Event`	The internal score model, with durations held as exact rationals.
`Music::NWC2MusicXML::MusicXML`	Score to MusicXML 4.0 document.
`Music::NWC2MusicXML::Diagnostics`	The message catalogue and the `carp`/`croak` helpers behind every warning and error.

Each of those can be used on its own. The Perl API page shows the three-stage pipeline that convert performs.

A distribution-managed Perl

If perl belongs to your operating system, install into a local::lib or a perlbrew rather than over the top of it: cpanm --local-lib=~/perl5 Music::NWC2MusicXML, then add that library's bin to PATH. The same advice applies to a Perl that a packaging system will overwrite at its next upgrade.