After finding out how hard it was to get JRuby running on the JVM, I looked at Grails and got it working right away. Did a couple of internal projects for my company with it. Used it again this past week. If you are stuck on the JVM, it's a great way to get the dynamic features that you miss on python or ruby. Lots of legacy products can evolve thanks to Groovy
Picked up GRAILS and those GROOVY while spiking ideas for a DBMS CMS system. Ended up really using GROOVY in a GRAILS RSS Mashup to track build server statuses from SCRUM server feeds. Powerful, spoils me and I love the XML slurper! But slow, soooo slow due to runtime layers. Ruby is my new script friend... But in a Java shop Groovy and Grails are good to have.
I had to write, really quickly, a desktop app. Found griffon, which is a rails-like framework to write desktop JVM apps. I was productive immediately and I really liked it. Brought me and Java back on speaking terms.
Started learning this for gig that never materialized. Seemed like pure win... until I compared the speed to some plain Java code.
It's a good idea, but you sacrifice a lot of performance to get a little convenience.
