Conference management software (preferably open source) with custom fields I've been told to set up software to organize a workshop. Is there (preferably an open source) conference solution that allows for:


Abstract Submission
Event Planning
Arbitrary user data-fields


Apparently managing "dietary requirements" is a really big deal for the organizers.
According to the developer, the non-free version of easychair can support something like this:


  We have a similar functionality in the registration module (non-free).
  All your requirements are related to conference registration, not to
  paper submission.


However, the "registration module" is very difficult to find.