Hoed - A Lightweight Haskell Tracer and Debugger

Hoed is a tracer and debugger for the programming language Haskell. To locate a defect with Hoed you annotate suspected functions and compile as usual. Then you run your program, information about the annotated functions is collected. Finally you connect to a debugging session using a webbrowser. See the

Project homepage

for more information on what it does and how you can use it to find bugs in your code.