Updated Contributor Docs

Over the last few weeks we have updated and overhauled the “Contributing” section on the osm2pgsql website. We want to make it easier for users and contributors to understand what our plans are for osm2pgsql, what are the open issues and what you can do to help.

The new Contributing Overview no longer focuses on coding because there are so many more ways to help the project than with code. Whether you are a user, have ideas on improving the documentation, or want to show your use case, everything helps to make osm2pgsql better.

We have also updated the road map with the most important milestones for getting to the next major release 3. If you are looking at a concrete project to work on, have a look at the updated project ideas.