According to the announcement, the event is sponsored by “the Queen’s Printers Association of Canada (QPAC) and the Open Data Society of BC.”
Here is the description of the event:
It’s a chance to build mobile or online applications using legislative data from across the provinces of Canada.[...]
The goal is to share the experience, findings, and difficulties of creating online apps based on legislative data published by the different Queen’s Printers of Canada. Present your apps and experience to representatives of the annual QPAC conference from across Canada! Your app and presentation may change the way other provinces look at legislative data, online licensing and open data policies!
What are we building?
Anything you like! It would be great if it uses legislative data. We want to see what you can come up with! Focus on multiple jurisdictions, or just one.
For more information, please see the announcement.