This year on August 27-29 the OpenSym conference on open collaboration will take place in Berlin:
The 10th International Symposium on Open Collaboration (OpenSym 2014) is the premier conference on open collaboration research and practice, including open access, open data, open educational resources, IT-driven open innovation, open source, wikis and related social media, and Wikipedia research and practice. Learn more about OpenSym 2014 and the OpenSym conference series.
Each track has its own submission site, which you can find on EasyChair. Please select the appropriate track. Submission deadline is April 20th, 2014. The deadline for submitting to the doctoral symposium is June 1st, 2014.