Free exchange server antivirus software for linux

DeniX Server OS is an independent Linux based distribution built from scratch by Denis Salmanovich. They aim to offer a user-friendly full-featured server operating system, pre-configured, well structured and easy to work with, and filled with the latest stable versions of Linux apps.
Its easy to install and configure. Every package is downloaded from the authors source and compiled when installed.
Main features:
- Domain Controller
- ADSL/CABLE Router (PPPoE)
- Network Firewall
- Anti Virus Gateway
- Anti Spam Gateway
- Mail Server (local & external) + Web Mail
- Calendar Sharing Support
- Network File Server
- DHCP Server
- TFTP BOOT Server
- WINS Server
- FTP Server
- VPN Server
- DNS Server
- DDNS Server
- MySQL Server
- HTTP Apache Server
- Remote Backup Solutions
- Remote control and administration
- Print Queue Server
- Proxy Server

C++ Server Pages is a partial Java server pages and servlet implementation in C++. C++ Server Pages is written as Apache 2.0 modules, with the focus on performance.

Campus Chat Server project is a chat server intended for use in the Cadiz University campus network.
Enhancements:
- hash_maps are now used instead of maps, so the cost of lookup or insertion is O(1) in the average case, instead of O(logn).

pDonkeyS is Perl implementation of an eDonkey server. The main goal of the server is to provide framework for further eDonkey protocol exploration, but it could be useful in testing of client software, since the server can be configured to output very detailed debugging info about eDonkey traffic.

This server was made to provide framework for further eDonkey protocol exploration, but it could be usefull in testing of client software, since the server can be configured to output very detailed debug info about eDonkey traffic.

iConnect Portal Server is a data presentation and delivery system for building enteprise portals over the iConnect Web Application Server.
Users of the platform have a customized single point of access to the companys information system and resources.
Main features:
- Grid / slots / blocks logic
- Modular structure
- Encapsulation of pages, blocks and classes inside modules
- Separation between view and model
- PHP as template engine
- Localized templates
- Grid themes
- Sessions

Darwin Calendar Server provides a CalDAV server.

The Darwin Calendar Server is a standards-compliant server that allows multiple users to collaboratively share calendaring information. It provides a shared location on the network to store schedules, and allows users to send each other and manage invitations.

In order to provide interoperability with multiple calendaring clients, the server implements the CalDAV protocol, which is an extension of WebDAV, which is in turn an extension of HTTP.