Reply from Arthur Snoke regarding the question under what license "iapsei-tau"
(http://www.iris.edu/pub/programs/iaspei-tau/) is available:

I am far from expert on licensing details.

Beginning in 1992 the software was accessible without qualification from USGS
Web sites (Buland and Engdahl were USGS), and I think that it is still available
from Brian Kennett's ANU Web site.  The only changes I have made were inspired
and/or cleared by the original authors.

It has been used in many packages, and I do not recall licensing even being
mentioned.

I hope this helps.

Arthur
