If you use VisualWorks, you might find the Blue Magic tools of interest - watch these two screencasts they've pushed up. They are a bit old (2 years), but I hadn't seen them before:
Apparently, Koans are interactive tests, and they are fairly popular with the "mainstream languages". I got an email today pointing to this start at a GNU Smalltalk set of them
SMALLTALKS 2011
5th International Conference on Smalltalk Technologies
Research Track: Call for Papers
November 3th - 5th, 2011
Important dates:
Submission (Hard Deadline): August 22th, 2011 (Argentinian time:
UTC/GMT -3 hours).
Notification of acceptance: September 23th, 2011.
Camera Ready Submission: October 7th, 2011.
We are pleased to announce the release of Seaside 3.0.5. This is a minor release for Seaside 3.0 that introduces Pharo 1.2 and jQuery 1.6 support. We recommend all users of Seaside 3.0 to update. A changelog is available