8 LPTV's in Boston?

[Don A]

This recent Globe article about the digital conversion coming up had this 
line:

"In addition, there are dozens of low-power TV stations, including eight in 
the Boston area, that are exempt from the changeover. To keep watching these 
channels, users will need converter boxes with an analog pass-through 
feature, but not every converter will include that feature."

Are there EIGHT LPTV stations licensed to Boston?  I'm surprised!  Not that 
I could pick any up way up here in the Green Mountain state...but I thought 
I would've heard about them in one way or another.

Anyone know what they are?  What they do for programming?  And when they 
came about?