Skip to content


Subversion checkout URL

You can clone with
Download ZIP
Run JavaScript code from Ruby
Ruby JavaScript Shell
Pull request Compare This branch is 225 commits behind rails:master.
Failed to load latest commit information.
lib ExecJS 1.2.9
test Merge test files
.gitignore Add Gemfile
.travis.yml Lets be serious
Gemfile Only install johnson on 1.8
LICENSE ExecJS 0.1.0 Proper capitalization for SpiderMonkey
Rakefile Formatting
execjs.gemspec Automagic files


ExecJS lets you run JavaScript code from Ruby. It automatically picks the best runtime available to evaluate your JavaScript program, then returns the result to you as a Ruby object.

ExecJS supports these runtimes:

A short example:

require "execjs"
ExecJS.eval "'red yellow blue'.split(' ')"
# => ["red", "yellow", "blue"]

A longer example, demonstrating how to invoke the CoffeeScript compiler:

require "execjs"
require "open-uri"
source = open("").read

context = ExecJS.compile(source)"CoffeeScript.compile", "square = (x) -> x * x", :bare => true)
# => "var square;\nsquare = function(x) {\n  return x * x;\n};"


$ gem install execjs


Copyright (c) 2011 Sam Stephenson and Josh Peek.

Released under the MIT license. See LICENSE for details.

Something went wrong with that request. Please try again.