Transformations API has no dependencies, but won't do anything for you unless you also get a user interface that makes use of it.

In order to enable Transformations UI, you need Earl Miles' Chaos tool suite installed.

If you've got jQuery UI installed, Transformations UI will support dragging around operations and connecting input/output slots with simple drag&drop instead of clicking the connection endpoints one by one. (Mind to get your jQuery UI tarball directly from Google Code and not from jqueryui.com itself, as the custom downloads from the latter don't ship with packed and minimized versions of the all the .js files. Which would cause jQuery UI not to work with default settings.) Transformations UI is equally happy with the jQuery UI versions 1.6 and 1.7, so it's your choice which branch you want to install.