Support feedback: I haven't explored this one much but thought I'd report it as I've noticed if a few times over the last few days. When I'm stepping though some Java run in the GWT shell and I decide to stop the shell process with the Stop button in the IDEA debugger, both IDEA and the process being debugged just hang. If I "Force Quit" the GWT shell (aka: kill -9) then it actually exits and IDEA resumes. If I'm not stepping though code when I click Stop then everything works as it should. I'm not sure if this is related to GWT needing -XstartOnFirstThread or maybe it's use of SWT and an embedded browser. I haven't noticed this problem with other pure Java apps I've been debugging.