This is a front end for an event management system that displayed alerts in real time for engineers to take action on. I used ExtJS 4 as the widget framework and Grails for the backend.
ExtJS has a lot of really cool widgets that come designed nicely out of the box. A proof of concept can be deveopled very quickly. Once you start adding a lot of content the code base can become overwhelming if you do not adhere to a good folder and file structure. This was specifically for the desktop on an intranet site, so network speed was not a problem. However, if it were available on the internet the file size of the ExtJS library could be a potential problem. Additionally, mobile would not be supported out of the box.