Gant is Groovy Ant Scripting
Gant is a tool for scripting Ant tasks using Groovy instead of XML to specify the logic. A Gant specification is a Groovy script and so can bring all the power of Groovy to bear directly, something not possible with Ant scripts. Whilst it might be seen as a competitor to Ant, Gant uses Ant tasks for many of the actions, so Gant is really an alternative way of doing things using Ant, but using a programming language rather than XML to specify the rules.
Here is an example Gant script:
In this script there are two targets, stuff and otherStuff -- the default target for this build is designated as stuff and is the target run when Gant is executed from the command line with no target as parameter.
Targets are closures so they can be called as functions, in which case they are executed as you expect, or they can be dependencies to other targets by being parameters to the depends function, in which case they are executed if an only if they have not been executed already in this run. (There is a page with some more information on Targets.)
You may be wondering about the stuff at the beginning of the script. Gant has two ways of using pre-built sub-scripts, either textual inclusion of another Gant script or the inclusion of a pre-compiled class. The example here shows the latter -- the class gant.targets.Clean is a class that provides simple clean capabilities.
The default name for the Gant script is build.gant, in the same way that the default for an Ant script in build.xml.
Gant provides a way of finding what the documented targets are:
The messages on this output are exactly the strings associated with the target name in the introduction to the target.
Gant "eats its own dog food"
Gant can build and install itself and is being used for various build tasks including building Groovy and Java programs, static websites, LaTeX documents. The ability to have arbitrary Groovy methods within the build scripts makes a Gant build script so much easier to work with that the mix of XML and Groovy scripts that using Ant necessitates. But then maybe this is an issue of individual perception. But then Gant is not about replacing Ant, it is about having a different way of working with the tasks and infrastructure that Ant provides.
Prepackaged Distributions are for those who want to "load and go".
Developer Access is for those who want to be right on the cutting edge.
If you give Gant a go and have some feedback, do let us know on the Gant User mailing list or perhaps the Groovy User mailing list.
If you have any issues with Gant then please add a JIRA issue into the Gant JIRA at Codehaus. The URL is http://jira.codehaus.org/secure/CreateIssue!default.jspa