Digital Libraries Database and Club discussion

Wikipedia has several articles directly relating to digital libraries on-line. Their main article is at:

http://en.wikipedia.org/wiki/Digital_...

The following URL leads to Wikipedia's article listing on-line digital libraries from around the world:

http://en.wikipedia.org/wiki/List_of_...

The following is wikipedia's list of on-line encyclopedias from around the world:

http://en.wikipedia.org/wiki/List_of_...

If you yourself have any good or bad experiences with any of these libraries, be so kind as to describe them in a post to this group.