Many developers utilize Eclipse for editing Ant files. Ant editor in Eclipse is fairly powerful, this article provides a good overview of its capabilities.

One of the most useful features is auto-complete for Ant tasks. Just press Ctrl-space and you'll see all attributes and nested elements supported by the task.

Auto-complete comes very handy when working with DPBuddy Ant tasks (and for developing WebSphere DataPower-related artifacts in general).

Just type '<dp:' (assuming that this is the prefix you assigned to DPBuddy's antlib) and then Ctrl-space and you'll see the list of all DPBuddy's tasks. Pressing Ctrl-space anywhere after the name of the task shows the list of attributes or nested elements.

Using auto-complete to see list of attributes for dpimport

Unfortunately, auto-complete won't display help for custom tasks. Apparently description of Ant tasks is embedded inside Eclipse and does not seem to be extendable.