Corona's development tools are hosted on SourceForge.
Our development philosophy is that everything should be well-tested. Corona has a set of unit tests (using CppUnit) that verify basic API functionality and correct image loading. For example, every image in the bmpsuite is compared with reference PNG images. If the loaded images don't match, the test fails. When a bug is found, tests are added to make sure it never appears again. Unit testing guarantees quality software with every release.