Symfony 2.4 comes with a great form debugger panel in the Symfony Profiler. That was probably one of the most loved feature
introduced in 2.4.
In Symfony 2.5, this form debugger panel UI gets even better with a collapsible
form tree on the left and collapsible sections on the right; the browser even
remembers which layers were collapsed or expanded after a refresh. The UI is
also cleaner and easier to understand with interesting information expanded by
default, and erroneous fields also highlighted.