The new version of Grunt has been changed by removing all the built-in tasks and replacing them with the equivalent officially maintained, standalone plugins.
According to a post on the Bocoup blog by Tyler Kellen, who co-maintains Grunt with Ben Alman:
“One of the biggest benefits of this change is faster iteration. It’s no longer necessary to ship a new version of Grunt for every minor plugin change! If jshint gets updated, for example, we can just release a new version of grunt-contrib-jshint.”
He also says that with the core plugins separated, the barrier to entry for collaboration is lower than ever.
Another major change from Grunt v0.3.x is that Grunt no longer ships with a binary. Instead of installing Grunt globally, you now specify it as a development dependency in your project’s package.json file, along with any Grunt plugins you might be using.
Grunt 0.4 also has a new website with much more documentation and tools for discovering useful plugins. Grunt only began in March 2012, and is now achieving over 60,000 downloads a month.