GridCalendar (abbreviated as GriCal) is a community website where anyone can share information about interesting events. It has a strong focus on scientific and  FOSS-related conferences, using  Free Software, and  Free Data, and  Free Formats.

In the past we used the name CloudCalendar (abbreviated as CloCa)



Basically, we created this project because we want to be able to openly and freely share events information and manage them within our calendars, communities and the world. The main features are:

  • Software freedom: The license of the software is free as in  Affero General Public License.
  • Data freedom: The license of the public data is free as in the  Creative Commons Licences
  • Community oriented:
    • Everyone can colaborate in the project
    • Everyone can create, update and delete events (log in and set a filter to be notified if someone changes an event you care about)
    • Everyone can create groups
  • documentation: We document our work including our design decisions and our analysis of other calendar sites, to ensure reuse of the data and experience.
  • Openness: All public data can be downloaded easily in several formats.
  • Diversity: There are several means for input and output to accomodate as many people as possible.
  • Internationalisation: We aim to be multilingual.

Support / help

We really need help. There are many ways to help the project. Some ideas:

  • Add events and improve the data of the current events
  • Easy and fast but costs money: donate
  • Maintain and improve our servers
  • Promote GriCal in conferences, etc.
  • improve the source code

Source Code

You can get the source code using

hg clone gridcalendar

Other Calendars

We have analysed some of the features of other online calendars. See OtherCalendars


See FeaturesList

Data Structure of an Event

See DataFormats

Alternative software

A list of foss software related to calendars:

Other non-free software:


Once this project is in a more advanced state, setting up an organisation will be necessary, like a German Limited ( Unternehmergesellschaft haftungsbeschränkt), which can also be for the public interest ( Gemeinnützigkeit). See also  Gemeinnützige Gesellschaft.

We document promoting activities and mentions of GridCalendar. See OnVisibility .


  • 2009-06-29: 1st Meeting at FFII Berlin office: Ivan, Mario, Sven
  • 2009-10-01: 2sd Meeting at FFII Berlin office: Ivan, Sven.
    • revamped the page. working on the features list.
  • 2010-02-23: As the code is almost in an usable state, a preliminary business for setting up the German Limited was registered.
  • 2012-01-02: Version 0.9 commited to the main repository

See also the automatically generated  Trac Timeline


Examples of potentially interested communities or calendars. See OnCalendars