From Jack's blog:
If you are programmer, you might remember the excitement when NotesPeek and NotesPing were first released. Well, LND is the definitive administration tool for Domino failure analysis and will be quite worthwhile to study.
It has some cool features, like recreating the server doc from a DXL dump, NSD file comparisons, and reading through all the semaphore locks.
It does come with a help document , but there isn't much hand holding--you are going to need to know the terms and architecture of Domino to really extract value from LND.
After a quick test drive, I agree. It does a good job of gathering all of the relevant information and presenting it in a friendlier format than the NSD. Kudos to IBM for releasing this. It won't tell you "Hey, here is exactly why you had this crash", but it will get you pretty close...