Today, I created a short video that explains some of the functionality of my weka-virtualenv tool (no audio, so look closely!):
I also made a new release (0.0.11), since I added a new tool that you can kick off with one or more dataset filenames. This tool, the Arff Command Selector, then allows you to select environment and command to execute. At this stage, the only commands are Explorer and Arff Viewer. Here is a screenshot:
This tool (wenvarff.sh or wenvarff.bat) makes it easier to integrate an action to context-menus of file browsers (aka Open with).