It is finished! io.js Version 1.0.1 (Beta stability) released!

As you know, io.js is focused on new versions of the V8 engine, which include support for the ES6 standard. While NodeJS had to use the --harmony flag and other problems to support ES6 in order to support new features, io.js provides 3 groups of innovations:

• shipping - innovations marked stable in V8, such as generators, templates, new string methods, etc. All of them are enabled by default and do not require special flags on startup.
• staged - almost completed, but not tested, or not converted to ES6. These are innovations from the category “use at your own peril and risk”, which require the launch flag --es_staging (or --harmony)
• in progress - all other innovations that must be enabled by an individual flag (for example --harmony_arrow_functions)

New features enabled by default:

• Blocks scope
  
  • let
  • const
  • functions in blocks (strict mode only)
  
  
• Collections
  
  • Map
  • Weakmap
  • Set
  • Weakset
  
  
• Generators
• Binary and octal literals
• Promises
• New string methods
• Characters
• String patterns

Innovations available with the --es_staging flag:

• Classes (strict mode only)
• Extended Objects
• Symbol.toStringTag (user-defined results of the fi-s Object.prototype.toString)

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More detailed (and, by the way, very extensive) documentation is available at iojs.org/api/all.html .