Wait: "Freely Available" *is* defined at the beginning of the license:
| "Freely Available" means that no fee is charged for the item. It | also means that recipients of the item may redistribute it under | the same conditions they received it.
Whoops. I missed that.
It seems that, if I want to distribute modified versions of the Library, I must place my modifications in the Public Domain (a non-free requirement, since it fails DFSG#3) _or_ otherwise distribute them without charging any fees (another non-free requirement, since it fails DFSG#1).
This only mandates that there be *a* no-cost way to obtain the modifications versions. It does not prevent additional mays to obtain the source. This still seems non-free. It is interesting that this clause fragment was removed: ' itself, though there may be fees involved in handling the item'.
If this is the case, I think that we lack free paths through this license and must conclude that VIGRA does not currently comply with the DFSG.