Developer Guide

For now, the main developer documentation is the Adding a New Format page. Take particular note of the section on error handling, but the entire page is worth reading.

The other developer docs may also be useful.

Contributing your code

First, if you are a new contributor to open-source software, please read this introduction to contributing patches upstream. Some of the technical details are obsolete, but the general principles are still valid.

Every contribution to OpenSlide must include a signoff certifying that you have the right to contribute your changes to the OpenSlide project. See this guide for details.

Please discuss your changes on the openslide-users mailing list or in a GitHub issue, before you are ready to submit them, so that we can help you integrate your code into the existing codebase.

When contributing support for a new format, we strongly prefer that you also contribute example slide files for our openslide-testdata repository. The example files must be data that you are entitled to contribute, and the OpenSlide project must receive permission to redistribute them with or without modification. Email the mailing list for instructions on how to accomplish this.

Original development guide

This section contains the original development guide written by Adam Goode in 2010, with some updates by Benjamin Gilbert in 2012 and 2013. It’s no longer actively maintained, but there’s still some wisdom here.


This document is for any contributors to OpenSlide, including those in the original OpenSlide group at CMU. It includes some guidelines and advice.


Release process

We have issue templates for each type of release. OpenSlide maintainers can perform a release by filing a new issue named after the new version to be released, and checking boxes.