Dawn

Dawn converts Address Books among various Address Book Programs.
Dawn is equipped with an extraction feature. It is absolutely free to use
and distribute in the form seen here, but the source code is not freely
distributable.
New in this release: Opera 8.x, Eudora 6.2.x, and Thunderbird 1.x support
Dawn works with the following programs:
Becky!, Pine (for PC and UNIX), Mozilla, Thunderbird, Netscape 6/7, Netscape Communicator 4.x, Netscape Navigator 3.x, Opera, Outlook Express / Windows Address Book (WAB), Outlook 98/2000/2002/2003, Palm Desktop, Simeon, ExecMail, Juno, Corel WordPerfect Address Book 8.x, Eudora 3.x, 4.x, 5.x, 6.x, Pegasus Mail 3.x and 4.x, Other programs which can use/import/export LDAP/LDIF, Comma Separated Value (CSV), vCard (VCF), plain text, one per line or comma separated formats or store addresses in a text file