Checking answers is possible though.

2+2 returning DONE is my personal favorite.

The tiddlylisp implementation is interesting. Seeing a Lisp compiler in my usual language (Python) is helpful. If nothing else, I'm really glad I read the article since I'm giving Lisp another try (via Land of Lisp, http://landoflisp.com/) after a 9 month hiatus.

Nice chair, but what's with the modified roomba?

it's called a turtlebot, just a simple trashcan robot that you can throw sensors on for basic research

The link was for the mobile slate site. This is the non-mobile version:

http://www.slate.com/articles/health_and_science/family/2013...