Presenters, working group chairs and RIPE Programme Committee members pay to attend the RIPE Meetings like all other attendees. In extraordinary circumstances, the RIPE Chair can waive the meeting fee for presenters. These requests are dealt with on a case-by-case basis via pc [at] ripe [dot] net.
If you are interested in presenting in one of the working group sessions, please get in touch with the working group chairs directly (click the “@” icon). If you’re not sure what kind of session you should be presenting at, read about the difference between Plenary and working group sessions.