There are lots of software-based calendar systems out there, nowadays. So you might ask, why we started developing a new one.
Some points constrast kaliko with existing calendars:

• Open Source
  Kaliko is and will be completely open source software, published under the terms of the GNU General Public License, Version 2.
  Unlike most other open source calendar projects, kaliko is actively developed and supported by a company.
• Standard Compliant
  Kaliko is based on open standards like iCalendar and XML. This increases interoperability with other systems and guarantees future compatibility.
• Webservice Based
  Kaliko fits perfectly into your existing SOA-infrastructure and strengthens the modularity and interchangeability of your IT.
• Platform Independent but Integrated
  Kaliko is written in Java and is therefore extremely platform-independent. Integrations for Desktop-environments like Windows, Mac OS X, KDE or Gnome and serveral mobile-platforms like J2ME, OpenMoko or Maemo will give you easy and unlimited access to your calendar-data from practically anywhere. A generic webinterface and a Webstart-Client complete the possibilities.
• Integrated Resource Management
  Kaliko can be linked with your existing resource-management-solutions to share resources and optimize your business.
• Usability
  Kaliko is not only intuitive and fast to use but also easy to setup. No hassles to install and configure - just start off!