edx.org DEV201x class sample repo for simple examples
For TSGulpDemo:
Per the video, if npm not yet installed, install nodejs or iojs
Then at a command prompt, install gulp:
npm install -g gulp
After that, go to the cloned TSGulpDemo directory and type:
npm install
gulp
This should start the watcher if everything is installed correctly. You can then start to edit files in the typescript directory, and see them show up as js in the js directory.