The variables view will show all the local and global variables and params that are currently in scope. There are two types of variables that can be views.
Variable Types
String - These contain text values. This could be strings of text, numbers, or other characters.
Nodesets - Nodesets are represented in the variables view as expandable variables. They contain sequences of nodes. The type of nodes are represented by icons for elements, attributes, text, comments or processing instructions.
Can I change the value of variables?
Currently the XSLT Debugger does not support changing the values or contents of a variable. All XSLT variables are read only.