Chris an I committed IDE project definitions for IntelliJ IDEA and Eclipse in the current development branch "master" on GitHub. the 3.0.x maintenance branch on the other hand does not include these changes. It's recommended to use IntelliJ as IDE which is also freely available. Eclipse has some limitations i.e. the inability to nest projects.
The new project definitions rely on a Git submodule link to the new echo3-dependencies Repository. This repository contains the required 3rd party JARs to build Echo. This eases building with Ant too, because now you do no longer need to pass environment variables to start the build successfully. A simple "ant" will work now now on the commandline.
The GitHub URL is https://github.com/echo3/echo3
To be sure that you have the latest sources and the submodule correctly populated be assure to run "git submodule update --init --recursive". Some Git tools might take care on their own.