How to run local program (exe) via Chrome via HTML/javascript
You can set a protocol like myapp://launch/activity or the like to automatically launch your app by setting up a registry key in HKEY_CLASSES_ROOT with the name of your protocol and the action it should take.
There is a MSDN article showing the following example of a registry for an alert protocol:
HKEY_CLASSES_ROOT alert (Default) = "URL:Alert Protocol" URL Protocol = "" DefaultIcon (Default) = "alert.exe,1" shell open command (Default) = "C:\Program Files\Alert\alert.exe" "%1"Which would then be called by requesting a url with alert:YOURPARAMS, which would then call alert.exe YOURPARAMS.