Files from the yeoman + requirejs config. See here the full tutorial: http://www.webdesignporto.com/3-steps-to-fully-automatized-javascript-environment-with-yeoman-and-require-js-for-lazy-people/

Gruntfile.js

// Generated on 2014-02-11 using generator-webapp 0.4.7
'use strict';

// # Globbing
// for performance reasons we're only matching one level down:
// 'test/spec/{,*/}*.js'
// use this if you want to recursively match all subfolders:
// 'test/spec/**/*.js'

module.exports = function (grunt) {

    // Load grunt tasks automatically
    require('load-grunt-tasks')(grunt);
    grunt.loadNpmTasks('grunt-requirejs');

    // Time how long tasks take. Can help when optimizing build times
    require('time-grunt')(grunt);

    // Define the configuration for all the tasks
    grunt.initConfig({
        requirejs: {
            dist: {
                options: {
                    baseUrl        : '<%= yeoman.app %>/scripts/',
                    name           : 'main',
                    mainConfigFile : '<%= yeoman.app %>/scripts/main.js',
                    out            : '.tmp/concat/scripts/main.js'
                }
            }
        },


        // Project settings
        yeoman: {
            // Configurable paths
            app: 'app',
            dist: 'dist'
        },

        // Watches files for changes and runs tasks based on the changed files
        watch: {
            js: {
                files: ['<%= yeoman.app %>/scripts/{,*/}*.js'],
                tasks: ['jshint'],
                options: {
                    livereload: true
                }
            },
            jstest: {
                files: ['test/spec/{,*/}*.js'],
                tasks: ['test:watch']
            },
            gruntfile: {
                files: ['Gruntfile.js']
            },
            compass: {
                files: ['<%= yeoman.app %>/styles/{,*/}*.{scss,sass}'],
                tasks: ['compass:server', 'autoprefixer']
            },
            styles: {
                files: ['<%= yeoman.app %>/styles/{,*/}*.css'],
                tasks: ['newer:copy:styles', 'autoprefixer']
            },
            livereload: {
                options: {
                    livereload: '<%= connect.options.livereload %>'
                },
                files: [
                    '<%= yeoman.app %>/{,*/}*.html',
                    '.tmp/styles/{,*/}*.css',
                    '<%= yeoman.app %>/images/{,*/}*.{gif,jpeg,jpg,png,svg,webp}'
                ]
            }
        },

        // The actual grunt server settings
        connect: {
            options: {
                port: 9000,
                livereload: 35729,
                // Change this to '0.0.0.0' to access the server from outside
                hostname: 'localhost'
            },
            livereload: {
                options: {
                    open: false,
                    base: [
                        '.tmp',
                        '<%= yeoman.app %>'
                    ]
                }
            },
            test: {
                options: {
                    port: 9001,
                    base: [
                        '.tmp',
                        'test',
                        '<%= yeoman.app %>'
                    ]
                }
            },
            dist: {
                options: {
                    open: false,
                    base: '<%= yeoman.dist %>',
                    livereload: false
                }
            }
        },

        // Empties folders to start fresh
        clean: {
            dist: {
                files: [{
                    dot: true,
                    src: [
                        '.tmp',
                        '<%= yeoman.dist %>/*',
                        '!<%= yeoman.dist %>/.git*'
                    ]
                }]
            },
            server: '.tmp'
        },

        // Make sure code styles are up to par and there are no obvious mistakes
        jshint: {
            options: {
                jshintrc: '.jshintrc',
                reporter: require('jshint-stylish')
            },
            all: [
                'Gruntfile.js',
                '<%= yeoman.app %>/scripts/{,*/}*.js',
                '!<%= yeoman.app %>/scripts/vendor/*',
                'test/spec/{,*/}*.js'
            ]
        },


        // Mocha testing framework configuration options
        mocha: {
            all: {
                options: {
                    run: true,
                    urls: ['http://<%= connect.test.options.hostname %>:<%= connect.test.options.port %>/index.html']
                }
            }
        },




        // Compiles Sass to CSS and generates necessary files if requested
        compass: {
            options: {
                sassDir: '<%= yeoman.app %>/styles',
                cssDir: '.tmp/styles',
                generatedImagesDir: '.tmp/images/generated',
                imagesDir: '<%= yeoman.app %>/images',
                javascriptsDir: '<%= yeoman.app %>/scripts',
                fontsDir: '<%= yeoman.app %>/styles/fonts',
                importPath: '<%= yeoman.app %>/bower_components',
                httpImagesPath: '/images',
                httpGeneratedImagesPath: '/images/generated',
                httpFontsPath: '/styles/fonts',
                relativeAssets: false,
                assetCacheBuster: false
            },
            dist: {
                options: {
                    generatedImagesDir: '<%= yeoman.dist %>/images/generated'
                }
            },
            server: {
                options: {
                    debugInfo: true
                }
            }
        },

        // Add vendor prefixed styles
        autoprefixer: {
            options: {
                browsers: ['last 1 version']
            },
            dist: {
                files: [{
                    expand: true,
                    cwd: '.tmp/styles/',
                    src: '{,*/}*.css',
                    dest: '.tmp/styles/'
                }]
            }
        },

        // Automatically inject Bower components into the HTML file
        'bower-install': {
            app: {
                html: '<%= yeoman.app %>/index.html',
                ignorePath: '<%= yeoman.app %>/'
            }
        },

        // Renames files for browser caching purposes
        rev: {
            dist: {
                files: {
                    src: [
                        '<%= yeoman.dist %>/scripts/{,*/}*.js',
                        '<%= yeoman.dist %>/styles/{,*/}*.css',
                        '<%= yeoman.dist %>/images/{,*/}*.{gif,jpeg,jpg,png,webp}',
                        '<%= yeoman.dist %>/styles/fonts/{,*/}*.*'
                    ]
                }
            }
        },

        // Reads HTML for usemin blocks to enable smart builds that automatically
        // concat, minify and revision files. Creates configurations in memory so
        // additional tasks can operate on them
        useminPrepare: {
            options: {
                dest: '<%= yeoman.dist %>'
            },
            html: '<%= yeoman.app %>/index.html'
        },

        // Performs rewrites based on rev and the useminPrepare configuration
        usemin: {
            options: {
                assetsDirs: ['<%= yeoman.dist %>']
            },
            html: ['<%= yeoman.dist %>/{,*/}*.html'],
            css: ['<%= yeoman.dist %>/styles/{,*/}*.css']
        },

        // The following *-min tasks produce minified files in the dist folder
        imagemin: {
            dist: {
                files: [{
                    expand: true,
                    cwd: '<%= yeoman.app %>/images',
                    src: '{,*/}*.{gif,jpeg,jpg,png}',
                    dest: '<%= yeoman.dist %>/images'
                }]
            }
        },
        svgmin: {
            dist: {
                files: [{
                    expand: true,
                    cwd: '<%= yeoman.app %>/images',
                    src: '{,*/}*.svg',
                    dest: '<%= yeoman.dist %>/images'
                }]
            }
        },
        htmlmin: {
            dist: {
                options: {
                    collapseBooleanAttributes: true,
                    collapseWhitespace: true,
                    removeAttributeQuotes: true,
                    removeCommentsFromCDATA: true,
                    removeEmptyAttributes: true,
                    removeOptionalTags: true,
                    removeRedundantAttributes: true,
                    useShortDoctype: true
                },
                files: [{
                    expand: true,
                    cwd: '<%= yeoman.dist %>',
                    src: '{,*/}*.html',
                    dest: '<%= yeoman.dist %>'
                }]
            }
        },

        // By default, your `index.html`'s <!-- Usemin block --> will take care of
        // minification. These next options are pre-configured if you do not wish
        // to use the Usemin blocks.
        // cssmin: {
        //     dist: {
        //         files: {
        //             '<%= yeoman.dist %>/styles/main.css': [
        //                 '.tmp/styles/{,*/}*.css',
        //                 '<%= yeoman.app %>/styles/{,*/}*.css'
        //             ]
        //         }
        //     }
        // },
        // uglify: {
        //     dist: {
        //         files: {
        //             '<%= yeoman.dist %>/scripts/scripts.js': [
        //                 '<%= yeoman.dist %>/scripts/scripts.js'
        //             ]
        //         }
        //     }
        // },
        // concat: {
        //     files: [{
        //         dest: '.tmp\\concat\\scripts\\main.js',
        //         src:
        //         ['{app,.tmp}\\bower_components\\requirejs\\require.js',
        //          '{app,.tmp}\\scripts\\main.js' ]
        //     }]
        //     dist: {}
        // },

        // Copies remaining files to places other tasks can use
        copy: {
            dist: {
                files: [{
                    expand: true,
                    dot: true,
                    cwd: '<%= yeoman.app %>',
                    dest: '<%= yeoman.dist %>',
                    src: [
                        '*.{ico,png,txt}',
                        '.htaccess',
                        'images/{,*/}*.webp',
                        '{,*/}*.html',
                        'styles/fonts/{,*/}*.*',
                        'gAssets/{,*/}*.{jpg,jpeg,png,mp3}',
                        'bower_components/' + (this.includeCompass ? 'sass-' : '') + 'bootstrap/' + (this.includeCompass ? 'fonts/' : 'dist/fonts/') +'*.*'
                    ]
                }]
            },
            styles: {
                expand: true,
                dot: true,
                cwd: '<%= yeoman.app %>/styles',
                dest: '.tmp/styles/',
                src: '{,*/}*.css'
            }
        },


        // Generates a custom Modernizr build that includes only the tests you
        // reference in your app
        modernizr: {
            devFile: '<%= yeoman.app %>/bower_components/modernizr/modernizr.js',
            outputFile: '<%= yeoman.dist %>/bower_components/modernizr/modernizr.js',
            files: [
                '<%= yeoman.dist %>/scripts/{,*/}*.js',
                '<%= yeoman.dist %>/styles/{,*/}*.css',
                '!<%= yeoman.dist %>/scripts/vendor/*'
            ],
            uglify: true
        },

        // Run some tasks in parallel to speed up build process
        concurrent: {
            server: [
                'compass:server',
                'copy:styles'
            ],
            test: [
                'copy:styles'
            ],
            dist: [
                'compass',
                'copy:styles',
                'imagemin',
                'svgmin'
            ]
        }
    });


    grunt.registerTask('serve', function (target) {
        if (target === 'dist') {
            return grunt.task.run(['build', 'connect:dist:keepalive']);
        }

        grunt.task.run([
            'clean:server',
            'concurrent:server',
            'autoprefixer',
            'connect:livereload',
            'watch'
        ]);
        // var server = require('./server/index.js');
        // server.use(require('connect-livereload')({
        //     port: 35729
        // }));
    });

    grunt.registerTask('server', function () {
        grunt.log.warn('The `server` task has been deprecated. Use `grunt serve` to start a server.');
        grunt.task.run(['serve']);
    });

    grunt.registerTask('test', function(target) {
        if (target !== 'watch') {
            grunt.task.run([
                'clean:server',
                'concurrent:test',
                'autoprefixer',
            ]);
        }

        grunt.task.run([
            'connect:test',
            'mocha'
        ]);
    });

    grunt.registerTask('build-rjs', [
        'requirejs:dist']);

    grunt.registerTask('build', [
        'clean:dist',
        'useminPrepare',
        'concurrent:dist',
        'autoprefixer',
        'concat',
        'requirejs:dist',
        'cssmin',
        'uglify',
        'copy:dist',
        'modernizr',
        'rev',
        'usemin',
        'htmlmin',
    ]);

    grunt.registerTask('default', [
        'newer:jshint',
        'test',
        'build'
    ]);
};

index.html

<!doctype html>
<!--[if lt IE 7]>      <html class="no-js lt-ie9 lt-ie8 lt-ie7"> <![endif]-->
<!--[if IE 7]>         <html class="no-js lt-ie9 lt-ie8"> <![endif]-->
<!--[if IE 8]>         <html class="no-js lt-ie9"> <![endif]-->
<!--[if gt IE 8]><!--> <html class="no-js"> <!--<![endif]-->
    <head>
        <meta charset="utf-8">
        <meta http-equiv="X-UA-Compatible" content="IE=edge">
        <title>g04</title>
        <meta name="description" content="">
        <meta name="viewport" content="width=device-width">
        <!-- Place favicon.ico and apple-touch-icon.png in the root directory -->
        <!-- build:css styles/vendor.css -->
        <script src="bower_components/modernizr/modernizr.js"></script>
        <!-- bower:css -->

        <!-- endbower -->
        <!-- endbuild -->
        <!-- build:css(.tmp) styles/main.css -->
        <link rel="stylesheet" href="styles/main.css">
        <!-- endbuild -->

    </head>
    <body>
        <!--[if lt IE 10]>
            <p class="browsehappy">You are using an <strong>outdated</strong> browser. Please <a href="http://browsehappy.com/">upgrade your browser</a> to improve your experience.</p>
        <![endif]-->



        <!-- build:js scripts/vendor.js -->
        <!-- bower:js -->
        <script src="bower_components/jquery/jquery.js"></script>
        <!-- endbower -->
        <!-- endbuild -->

        <!-- Google Analytics: change UA-XXXXX-X to be your site's ID. -->
        <script>
            (function(b,o,i,l,e,r){b.GoogleAnalyticsObject=l;b[l]||(b[l]=
            function(){(b[l].q=b[l].q||[]).push(arguments)});b[l].l=+new Date;
            e=o.createElement(i);r=o.getElementsByTagName(i)[0];
            e.src='//www.google-analytics.com/analytics.js';
            r.parentNode.insertBefore(e,r)}(window,document,'script','ga'));
            ga('create','UA-XXXXX-X');ga('send','pageview');
        </script>

        <!-- build:js scripts/plugins.js -->
        <script src="bower_components/sass-bootstrap/js/affix.js"></script>
        <script src="bower_components/sass-bootstrap/js/alert.js"></script>
        <script src="bower_components/sass-bootstrap/js/dropdown.js"></script>
        <script src="bower_components/sass-bootstrap/js/tooltip.js"></script>
        <script src="bower_components/sass-bootstrap/js/modal.js"></script>
        <script src="bower_components/sass-bootstrap/js/transition.js"></script>
        <script src="bower_components/sass-bootstrap/js/button.js"></script>
        <script src="bower_components/sass-bootstrap/js/popover.js"></script>
        <script src="bower_components/sass-bootstrap/js/carousel.js"></script>
        <script src="bower_components/sass-bootstrap/js/scrollspy.js"></script>
        <script src="bower_components/sass-bootstrap/js/collapse.js"></script>
        <script src="bower_components/sass-bootstrap/js/tab.js"></script>
        <script src="bower_components/requirejs/require.js"></script>
        <!-- endbuild -->

        <!-- build:js({app,.tmp}) scripts/main.js -->
            <script src="scripts/main.js"></script>
        <!-- endbuild -->
</body>
</html>

main.js

require.config({
    baseUrl: 'scripts',
    paths: {
    	'jquery': '../bower_components/jquery/jquery',
    },
    shim: {
    	'jquery': {
            deps: [],
            exports: '$'
        }
    }
});

require(['jquery', './Zombie.js'], function($, Zombie){
    // now you can do what you always done with $
    $('body').remove();
    // now you have the Zombie variable available in this context
    var zombie = new Zombie();
})
// Zombie is undefined here

Zombie.js

define([], function(){
	var Zombie = function(){
    	// zombie stuff
    }
    return Zombie;
})

Quick questions..

1. Does this create a single file even though you have two usemin blocks?
2. Why do you need two usemin blocks instead of putting it into one build:js?
3. Does this run through r.js to optimize your require logic? I'm finding I need to include require.js or else I get an error saying "define is not defined"

Is there a reason you're using grunt-requirejs vs grunt-contrib-requirejs?

requirejs: {
dist: {
        options: {
          baseUrl: '<%= yeoman.app %>/js',
          name: 'main',
          mainConfigFile: '<%= yeoman.app %>/js/main.js',
          out: '.tmp/concat/js/main.js',
          optimize: 'none',
          preserveLicenseComments: false,
          useStrict: true,
          wrap: true,
          mangle: false,
          paths: {
            requirejs: '../bower_components/requirejs/require'
          },
          include: 'requirejs'
        }
      }
}

Yeah, I'm also getting the "define is not defined" error.