LiveCycle ES4 provides support for rendering XFA-based forms into HTML5 such that the forms can be opened in browsers with HTML5 support, including those running on mobile devices like iPad. The HTML5 rendition of the forms maintains the layout of the form design and supports most form logic (such as JavaScript, form calc, and form validations) embedded in the XFA form template. This way, your technology investments in XFA forms are easily carried over to the devices where running the Adobe Reader plugin is not feasible.
For more information, see Upgrading to LiveCycle ES4, LiveCycle Mobile Forms documentation, and LiveCycle product documentation.