My work on the Sesame Street site included Liferay theme development for the public facing site as well as the internal corporate site. I spent roughly six months on the project in which time I used CSS, JavaScript, Velocity Templates, and XHTML to convert the site from Liferay 5.2.3 to Liferay 6.1.
The main improvement made during this project was the reduction of code by more than 3,000 lines which drastically improved the speed of the site.