LEAP can be downloaded from a large number of FTP sites from around
the world. The main Linux archives of sunsite.unc.edu, and tsx.mit.edu
all hold LEAP in apps/databases and source/usr.bin respectively. 

These sites are mirrored extensively around the world, a brief list is
included below.

ftp://ftp.demon.co.uk/pub/compsci/databases/leap
ftp://sunsite.unc.edu/pub/Linux/apps/databases/relational
...

See the LEAP web page for more (& current!) links.
http://www.dogbert.demon.co.uk/leap.html

