Lightweight Contact Manager (LiCoM) is a Web-based contact manager. It uses an LDAP server to authenticate users and keep data, making it possible for email clients and other LDAP-enabled software to access the contacts. People with an entry in the database can be asked to review and edit their own record, which may help with keeping information up to date. Other features include ogranization of contacts in groups, export to the vCard format, and printing of groups or all contacts.
The QmailToaster is an RPM-based Qmail distribution for CentOS, Fedora, SuSE, and Mandriva. This system is designed for ease of deployment and includes strong anti-spam systems. This includes support for SRS, SPF, DomainKeys, and virtual hosting on the SMTP side. On the user side, this has a Web-based administration interface and supports POP3, POP3 over SSL, IMAP, and IMAP over SSL.
VCF2alias is a tool to extract name and email information from VCF attachments (automatically if you use the enclosed mailcap), and writes a line (user-defined) to a file (user-defined). Originally, VCF2alias was aimed at mutt, but it should now work with any mail program that has text-file alias definitions.
Wallal is a standalone LDAP-to-Web gateway. It allows you to search, add to, modify, and delete from an LDAP database. It can format entries and validate them upon submission, and the entries displayed are fully configurable. It was designed with a "personal" LDAP server in mind (one that is used primarily as a phonebook). However, it should be reasonably easy to modify it to do more complex operations on a directory.