NnorTuX has put together a groupware solution for small and medium sized companies. It includes most of the tools needed in a groupware solution

NTX will provide the user with the following services:

• Calendar, shared calendar, share calendar with your colleagues
• Contacts, shared contacts, share contacts with your colleagues
• Tasks, assign tasks to colleagues
• E-mail, webmail, including antispam and antivirus
• Chat, chat with your colleagues
• File and print server
• Filetransfer FTP server
• Webproxy
• DNS, nameserver, create your own internal hostnames
• PDF-Printer Create PDF documents
• VPN server (choose between PPTPD or OpenVPN)
• Easy managment
• Monit
• Munin
• Linbox management Console

NTX is buildt on well know open source software