fCluster is a multi-threaded client/server redundancy application for your Linux firewall solution. fCluster is designed for the production environment with features that include: dynamic firewall synchronization, support for both ipchains and netfilter, user definable polling intervals and fail-over sequence, and email notification of a system failure. It also includes a Perl administration utility that allows you to configure both the server and the client from one machine, and view the status of the local and remote machines.
SurgeMail is a next-generation Mail Server. It combines features, performance, and ease of use into a single integrated product. It supports all the standard protocols, such as IMAP, POP3, SMTP, SSL, and ESMTP. It supports several anti-SPAM features which include friend-lists, black-lists, email postage using centipaid, smite, and more.