JRebel

Recently, I tried an awesome an Tool - JRebel. It saves a lot of time of compile and deploy our project. In my case, I have to package a war file for my project and copy that from dist folder in our SDK plugins to tomcat/deploy folder. This is very time-consuming and not productive. Our team leader introduced this product for me and helped me set up it. All changes will be directly push into JVM, I just need to refresh the page, all changes are showed up. It's really cool, right!  http://zeroturnaround.com/

Unfortunately, it's not free!