Looks like a Java webapp running on top of jetty [1]. Interesting - that's a quick and easy deployment. I wonder what are the hosting requirements and performance implications.
[1] https://builtwith.com/?http%3a%2f%2fgitplex.pmease.com%2fdem...
[1] https://builtwith.com/?http%3a%2f%2fgitplex.pmease.com%2fdem...