JTR is a light weight tool which can be used by automation tester and test developers.
First of all it uses high-capacity script language - Java.
The second is that it is very simple in using and configuration.
To start working with JTR you need just some experience in Java, knowledge of XML, comfortable IDE, application under test and a big wish to automate your tests.
Nice command line tool. I use it two years already and feel quite happy. It is very easy to use. Only one disavdantage is that there is no any plugins for IDEs and you have to do a lot of manual work to write tests.