These servers are for middle or litte enterprises.
Some management softwares can be installed or created :
SUGAR CRM ou V TIGER are you Customer Relationships Management
LAURUX, OPEN SI are you Finance Management
OPEN OFFICE ou LOTUS SYMPHONY are some office softwares
MOZILLA THUNDERBIRD is your mail client
Creating your own software
These softwares can be installed in your own enterprise. Some of them can be on my personal server.