I am pretty sure I've heard of Light Table here a few times. It's hard to be sure though since Microsoft's LightSwitch (see http://msdn.microsoft.com/en-us/vstudio/ff796201.aspx) which is almost identically named and has almost the identical purpose. That is, making programming easier for everyone including non-programmers.

I was about to forward this to a friend of mine who has several ideas for web startups but lacks all technical skills and is therefore waiting for the time "any day now" that non-programmers will be able to generate programs as fast, cheap and maintainable as programmers. But then I saw the website and realized he would have no idea what the heck it is from their elevator pitch:

http://www.lighttable.com/

Light Table is a new interactive IDE that lets you modify running programs and embed anything from websites to games. It provides the real time feedback we need to not only answer questions about our code, but to understand how our programs really work

That has to be about the least useful description of what it does I can think of.