"Serious Educational Game Online" ~ "...an incredibly versatile and globally unique educational games authoring engine. This game allows you to play, edit, create and even share games with other members of the Thinking Worlds™ community. Thinking Worlds is based on well researched and proven learning principles and has already been used to develop highly engaging games in many subject areas. This is your chance to take part in a GLOBAL six month BETA trial of this new exciting learning-based game for FREE."
Here's an article about Thinking Worlds from the blog: Educational Technology & Life.