title: Are there any .NET CLR/DLR implementations of ECMAScript?
body: <p>Does anyone know of <em>real</em> (i.. no vaporware) implementations of ECMAScript targeting the <strong>.NET CLR/DLR</strong>? Ideally something like <strong>what Rhino is for Java</strong>. A solid port of Rhino running on .NET Framework / Mono Framework would be perfect.</p>
  
  <p>I've only seen a handful of projects mentioned but never seen any come to light or in reality anything that I've ever been able to run script on.  Here's what I know about already:</p>
  
  <ul>
  <li><p><strong><a href="http://msdn.microsoft.com/en-us/library/hbxc2t98(VS.85).aspx" rel="noreferrer">MSScriptControl ActiveX Control</a></strong>: AFAIK, this was Microsoft's last real ECMAScript-compliant implementaiton (runs JScript 5.7). I've integrated with MSScriptControl but don't consider COM interop to be an answer to this question. x64 is a killer for this option.</p></li>
  <li><p><strong><a href="http://www.west-wind.com/WebLog/posts/10688.aspx" rel="noreferrer">JScript.NET</a></strong>: I don't count JScript.NET as it could never successfully parse any of my real scripts. It seems to have trouble with closures.</p></li>
  <li><p><strong><a href="http://en.wikipedia.org/wiki/JScript#Managed_JScript" rel="noreferrer">Managed JScript</a></strong>: Sounds like what I want but it appears to be dead in the water. It was a major example implementation for the DLR but then got entangled with SilverLight and seems to have faded as a priority since 2007. Creditable sources on the status of this would be helpful.</p></li>
  <li><p><strong><a href="http://myjscript.codeplex.com/" rel="noreferrer">MyJScript</a></strong>: Built as a tutorial implementation for the DLR. Anyone know how complete of an implementation this is?</p></li>
  <li><p><strong><a href="http://jint.codeplex.com/" rel="noreferrer">Jint</a></strong>: JavaScript interpreter for .NET. <strike>Doesn't as of yet support Currying or <code>try</code>-<code>catch</code>-<code>finally</code>.</strike></p></li>
  <li><p><strong><a href="http://www.remobjects.com/roscript.aspx" rel="noreferrer">RemObjects Script for .NET</a></strong>: An interesting contender still in the works. I'm confused by their marketing as to what it will actually be, but it sounds like it might eventually be a fit. If anyone knows more about it that would be helpful as well.</p></li>
  <li><p><strong><a href="https://stackoverflow.com/questions/356948/referencing-googles-v8-engine-from-a-net-app">V8 for .NET</a></strong>: This would be great if someone ported V8 to .NET.  As far as I know there isn't a large effort around this either. The link is to an idea for calling into it from a managed C++ wrapper.</p></li>
  </ul>
  
  <p>For background, I want to be able to execute JavaScript from within .NET; i.e. load up a set of scripts into context and call into that context and retrieve the execution results. Currently I jump through hoops to use MSScriptControl via cumbersome COM Interop. The inconsistency of COM makes it really tough for deployment and ensuring consistent execution.</p>
  
  <p>I'd like to be able to execute reasonably complex JavaScript test harnesses from within .NET. This isn't for creating user macros or simple tiny scripts; I need a real JavaScript environment like Rhino. If the implementation was running on top of the CLR (rather than COM) this would really help with some of the current issues.</p>