As a project for this year's advent, I will be making an open source contribution for each day of the period. I will focus on resolving bugs in Xdebug, PHP's DateTime extension and OpenStreetMap. I will also try to write a small article about the specific case to show how I fixed and/or contributed—providing it is interesting enough.
Each project has plenty of addressable issues (Xdebug bugs, DateTime bugs and OpenStreetMap notes) and I don't doubt other Open Source projects have a backlog of issues as well. Who joins me in contributing to your favourite Open Source project for the advent? Leave a comment below.