XMLSpear is a free XML editor with a great real-time validation feature.
It is easy to use, built in Java and available for all platforms.
XMLSpear is great for users that just want to edit or check XML files without deep knowledge of the XML syntax. The XML is displayed in three different views:
The treetable is great to see the structure of the xml file. Edit your xml files tag-free in this view and don't worry about typing reserved xml characters because it is all handled for you. You can insert and delete nodes, and even build a whole document from scratch. It is the most convenient view for correcting and editing xml. This view makes XMLSpear different form many other XML tools.
The element view is especially usefull if your element has many attributes.
The source view is great for correcting unwellformed xml, doing finds-replaces or copy-and-paste. You can always escape to this view to do advanced things that are not supported in the other views.
You can also validate and edit XML Schema (xsd) files.
Mac OS users can open and edit their plist files, even when they are in binary format.
XMLSpear is packaged with a MQSeries plugin for browing queues and putting messages, so you can even test your MQ based services.
You can extend the fuctionality by writing your own plugins written in Java, which is really very simple.
A sample plugin is now included in the download package !!