Compatibility Package Guidelines

Overview

Compatibility packages are packages which provide a secondary (usually older) version of an API or program from the primary version packaged within Fedora.

In general, software within Fedora should be moved to run on the current version of libraries. These guidelines illustrate some simple rules around how and why a compatibility package may be reasonable to include within Fedora.

Why not compatibility packages?

Shipping multiple versions of libraries tends to be problematic due to various reasons:

* multiple versions of a library could potentially be linked into one running process leading to unpredictable results.
* security changes, fixes, etc. must be applied multiple times.
* there is less incentive for dependent packages to update to use the newer API
* They also take more repository space, requiring more download of package metadata, ...

Exceptions

If there is a good reason why there should be a compatibility package, one _may_ be introduced if:

* there is someone who is willing to maintain the compatibility package
* the primary package maintainer is not against the idea
The reasoning for the latter is that even if the primary maintainer is not maintaining the compatibility package, chances are that they will have to be involved in the maintenance due to passing along security problems, helping out with things and redirecting misfiled bugs.