$ uglifyjs

node.js:216
        throw e; // process.nextTick error, or 'error' event on first tick
              ^
Error: Cannot find module 'uglify-js'
    at Function._resolveFilename (module.js:334:15)
    at Function._load (module.js:279:25)
    at Module.require (module.js:359:17)
    at require (module.js:370:17)
    at Object.<anonymous> (/home/ams/extern/UglifyJS/bin/uglifyjs:6:14)
    at Module._compile (module.js:434:26)
    at Object..js (module.js:452:10)
    at Module.load (module.js:353:31)
    at Function._load (module.js:310:12)
    at Array.0 (module.js:472:10)