Here's the start of Dart in NetBeans IDE. Basic Dart editing support is done and on saving a Dart file the related JavaScript files are automatically generated. In the context of an HTML5 application in NetBeans IDE, that gives you deep integration with the embedded browser and, even better, Chrome, as well as Chrome Developer Tools.

Below, notice that the "Sunflower Spectacular" H1 element is selected (click the image to enlarge it to get a better view), which is therefore highlighted in the live DOM view in the bottom left, as well as in the CSS Styles window in the top right, from where the CSS styles can be edited and from where the related files can be opened in the IDE. Identical features are available for Chrome, as well as on Android and iOS. And if you like that, watch this YouTube movie showing how Chrome Developer Tools integration can fit directly into the workflow below.

Anyone want to help get this plugin further? What's needed:

• Much deeper Dart editing support, i.e., right now only very basic syntax coloring is provided, i.e., an ANTLR lexer is integrated into the NetBeans syntax coloring infrastructure. Parsing, error checking, code completion, and some small code templates are needed.
  
• A new panel is needed in the Project Properties dialog on NetBeans HTML5 projects for enabling Dart (i.e., similar to enabling Cordova), at which point the "dart.js" file and other Dart artifacts should be added to the project, so that a Dart project is immediately generated and the application should be immediately deployable.
  
• Whenever changes are made to a Dart file, Dart should run in the background to create the Dart artifacts in some hidden way, so that the user doesn't see all the Dart artifacts as is currently the case.
• Some way of recognizing Dart projects (there's a YAML file as an identifier) and creating NetBeans HTML5 projects from that, i.e., from Dart projects outside the IDE.
  

I think that's all...

The official Dart Editor is based on Eclipse and requires a massive download of heaps of Eclipse bundles. Compare that to the NetBeans equivalent, which is a very small "HTML5 and PHP" bundle (60 MB), available here, together with the above small Dart plugin. Plus, when you look at how NetBeans IDE integrates with a bunch of Google-oriented projects, i.e., Chrome, Chrome Developer Tools, and Android (via Cordova), that's a pretty interesting toolbox for anyone using Dart. And bear in mind that ANTLRWorks, Microchip, and heaps of other organizations have built and are building their tools on top of NetBeans!