There are various macintosh, msdos/mswin, unix and some other computer
system programs for DNA sequence analysis available at the
archive sites including ftp.bio.indiana.edu (by anonymous ftp or gopher).
Several of these are free, some are shareware, and there are a few demos
of commercial programs here.
One of the free ones, called SeqApp, for Macintoshes, was written by Don
Gilbert (me). See the molbio/seqapp/ folder at the above archive.
Another mac sequence analysis program you might try is 'dnastacks'
I beleive that Will Gilbert, currently at U.New Hampshire,
also wrote a sequence editor for VMS computers a while back, and it
may have been called something like seqed. There are probably several
sequence editors with a name something like that (programmers
frequently name their software functionally, and not always very
-- d.gilbert--biocomputing--indiana u--bloomington--gilbertd at bio.indiana.edu