Unlike some other (canceled) conferences this year, the Open Design Alliance's World Conference is still taking place in Leiden, The Netherlands, in a month's time, April 27-29.
As a bonus, the ODA is giving away copies of the new OpenCAD (A Step by Step Guide to Developing a Professional CAD Application) book by Deelip Menezes AND Mr Menezes will be signing his book at the conference.
Conference costs $350 (incl. meals, excl. hotel), and now attendees get a $100 book for free.