djigger is a powerful open-source java profiler and 24/7 monitoring APM.

It allows us to diagnose performance problems in java programs extremely fast and perform most-mortem and offline analysis in production after crashes.

we use angularJS as one of the MVC frameworks for our client side GUI needs.

we use bootstrap to make our GUIs look nice and feel comfortable without investing too much time for visual design.

MongoDB is our prefered document store for pretty much all non-relational-heavy development. MongoDB scales beautifully and provides us with very polished api's and drivers. Easy to use, flexible and scalable.

Do I really need to explain? Well to me, the most appealing factor in Java besides the unbelievable community and vast array of available libraries, is just the amount of effort that has been put in the modern JVM. Decades of optimization and improvements have lead to a terrific piece of technology. I admire the people contributed to that.

We use django CMS for our primary website. It's flexible, easy to use, and it seems to perform very well.

We use Apache Http Server in conjunction with django. Apache is Apache for a reason.

Saves us a lot of time and headaches. Google groups is a powerful app. Gmail is just well thought-out and integrates well over multiple accounts.