The developers of open-source software toolkits should make every effort to maintain backward compatibility within its major versions (e.g., from Version 1.2 to 1.3). Specifically, the API of the existing methods should not change, the API of technologies used internal to the methods (e.g., the streaming system) will not change, and the API of new methods will conform to that of the existing methods.

Across major versions (e.g. from Version 1.x to 2.0), the APIs of the toolkit may change if it is in the best interest of the toolkit so as to provide effective implementations of the methods and features that are being sought by its users. Every API change will be well documented, and every effort will be made to provide scripts to facilitate the update user software that is affected by the API change.

Users are strongly encouraged to consult a toolkit's web pages and join its user's list to stay current on the changes occurring within the toolkit. Archiving your installation prior to upgrading to a new major version is also recommended.