Introducing Managed JScript

It’s finally released and I can blog about it. Have been waiting to write about it for some time now and now that it’s out, can talk about it.
Scott Guthrie in his keynote at MIX this week, announced that we are implementing a new version of JSscript implementation to run on top of the .NET platform. This would be called Managed Jscript. Managed Jscript will run on the new DLR, which also got announced at MIX, and interops well with other languages on DLR. So now the Jscript code, works well with not only C#, but also with IronPython , IronRuby, VB among other languages.

And this with the Silverlight platform, running cross browser, cross platform, would mean that the AJAX and other applications that were written with Jscript, would become more easier to write.

Checkout the cool talk about DLR and how various languages interop from Jim Hugunin and John Lam.  DLRConsole sample is a cool sample to try the new Managed Jscript and also it’s interop with other languages.

Comments (3)

  1. Gideon says:

    Javascript went dead on IE-7/Vista, need help

  2. Nate says:

    I really like the new Managed JScript – especially for the future possibility of developing stuff (right now playing with the ASP.NET futures release). I hope there will be more in-depth docs on it, as the things I’m finding via google (etc) are very limited in scope. In particular, I can’t seem to figure out how to extend the built in JS objects in a module and then have these changes applied in the page I include the module in. For example, I always extend the String object with a "trim" method:

    String.prototype.trim = function () {

       return this.replace(/^s+|s+$/g, "");


    This works great when I include this code in the page I’m working on. But if I try to include it in a module (even if I add it to a "init" function in the module and call that function at the start of my page), the String object is not extended and I get errors when I try to use it. This would be incredibly beneficial to be able to extend the primitive objects of JS application-wide.

  3. Why did you guys decide to completely drop Managed JScript?!?? There are so many developers that know JavaScript/JScript already (way more than Ruby) but yet you’ve decided to go forward with IronRuby for the DLR instead of Managed JScript.

    Here’s my full post/thoughts on this: