Eudora OSE is the Open Source Edition of one of the internet’s most pioneering and enduring applications. It is a re-imagining and re-implementation of classic Eudora features on top of the Mozilla Thunderbird codebase. It is more than just an extension, as certain functionality required changes to the core of the application. Some of these have been accepted into and become part of Thunderbird, while others are still awaiting acceptance. Eudora OSE integrates so tightly with specific versions of the underlying code that it is highly recommended for users to install the entire application, rather than trying to run the extension on top of Thunderbird.

Eudora OSE offers users the classic look and feel of the toolbars and menus they’re used to, plus more powerful interface customization than ever before. Where these options were formerly defaults limited to the particular operating system you were running, now both the 2- and 3-pane layouts from the classic Mac and Windows versions of Eudora are available in one integrated package. You can choose whichever one suits your taste or matches your operating system – all with just the click of a button.