What it does:
It is useful if you have a vocabulary in the form of a tree, eg it has terms within terms with nodes attached to them.
It will place all the first level terms in a block and when a term is clicked displays the tree below that term in another block.
If Panels is installed Taxonomy Split will install a minipanel with it's own layout. This has three columns, the first shows the first level, the second shows the children of the selected parent and the third column shows the teasers of any nodes found below the term selected.
The outputs are all themed and example css is provided.
Please report bugs and support requests on the Issues Page