Browserify + Reactify + watchify + gulpでReactの開発をする ref: http://qiita.com/ytanak/items/d81f7b1307058bd46fd2

gulpfile.js

'use strict';

var watchify = require('watchify');
var browserify = require('browserify');
var gulp = require('gulp');
var source = require('vinyl-source-stream');
var buffer = require('vinyl-buffer');
var gutil = require('gulp-util');
var sourcemaps = require('gulp-sourcemaps');
var assign = require('lodash.assign');
var reactify = require('reactify');

// add custom browserify options here
var customOpts = {
    entries: ['./src/main.js'],
    transform: [reactify],
    debug: true
};
var opts = assign({}, watchify.args, customOpts);
var b = watchify(browserify(opts));

gulp.task('js', bundle); // so you can run `gulp js` to build the file
b.on('update', bundle); // on any dep update, runs the bundler
b.on('log', gutil.log); // output build logs to terminal

function bundle() {
    return b.bundle()
        // log errors if they happen
        .on('error', gutil.log.bind(gutil, 'Browserify Error'))
        .pipe(source('app.js'))
        // optional, remove if you don't need to buffer file contents
        .pipe(buffer())
        // optional, remove if you dont want sourcemaps
        .pipe(sourcemaps.init({loadMaps: true})) // loads map from browserify file
        // Add transformation tasks to the pipeline here.
        .pipe(sourcemaps.write('./')) // writes .map file
        .pipe(gulp.dest('../../../../public/js'));
}