Tiny Vim plugin that turns your file into interactive worksheet:
This is just a first sketch of a plugin and it's not particularly pretty, but already quite handy. It requires though VIM compiled with ruby support. Just clone repository into your vim/bundle directory.
Files with extension *.scalaws are interpreted as worksheets and evaluated line by line with evaluation results added as comments to each line. ( It takes a second to evaluate first time because of lazy "scala" execution, but other lines are communicated directly with an existing worksheet instance.