1. Pollo interface is simple, friendly, support mouse tract, the most important thing is open source! Some of Its Features: java-based, and thus cross-platform. Pollo Has Been reported to work on Windows and Linux Variants, HP / UX11 and OS X. Drag-and-Drop of Nodes in and Between Files. Unlimited undo.
Multiple views on one file. Evaluation of XPath expressions. This is useful for searching nodes, but also as an XPath learning and experimenting tool. Customizability through plugins. Schema support, from DTD through XML Schema to Relax NG. Pollo also has its own simple Schema Language. Open Source, Mit License, Making It Free for Both Personal and Commercial USE.
To Learn More About Pollo, Follow One of these Links: http://pollo.sourceforge.net/