We didn't release it for a couple of reasons:

1) Proprietary implementation = bad

2) Inadequate discovery method for servers (relying on broadcast queries)

3) Uploading the entire index of files was expensive for modem users, and required a lot of extra work when the local file indexes changed (QRP solves this better, both technically and legally)

I think the LimeWire supernode implementation solves all of these problems and that's where we are going.