If you're not planning to make code changes and just want to run the latest prerelease version of Zotero (e.g. to take advantage of a recent bug fix or test a new feature), you can install a development XPI of Zotero. These XPIs are automatically generated every time a code commit is made and generally have not been rigorously tested.

Once you've installed a development XPI, you can update to the latest build at any time via Tools→Add-ons→Find Updates.

The 3.0 branch is the development line from which Zotero 3.0 releases are built. While 3.0 branch XPIs should be fairly safe to use, regular backups of your Zotero data are still highly recommended.

Note that dev XPIs will often not work with non-English versions of Firefox, as English strings added since the last release will not yet exist for other languages, resulting in XML or JavaScript errors. (English strings are merged into any locales that are missing strings at release time.) Changing the user interface language to “en-US” will allow you to use a dev build with missing non-English strings.

Install Zotero 3.0 Branch XPI

The trunk is the development line for Zotero 3.1 and later. The trunk contains experimental code, and there is a higher risk of experiencing data loss. You may not be able to revert to earlier XPI releases using the same data.

To safely test development code, set up a separate Firefox profile and install the trunk XPI into that. If you use Zotero syncing in your main profile, you should either not use syncing in the test profile or use a separate test account.

Note that dev XPIs will often not work with non-English versions of Firefox, as English strings added since the last release will not yet exist for other languages, resulting in XML or JavaScript errors. (English strings are merged into any locales that are missing strings at release time.) Changing the user interface language to “en-US” will allow you to use a dev build with missing non-English strings.

Using a trunk XPI with important data is strongly discouraged.

Install Extension Trunk XPI

At certain times, the Zotero trunk may require trunk versions of the word processor integration plugins. If this is the case, you'll receive an incompatibility error when you try to use the integration plugin.

While development versions of the word processor integration plugins can potentially cause corruption of Zotero fields within word processor documents, they will not cause any data loss within Zotero itself.

Install MacWord Integration Trunk XPI
Install WinWord Integration Trunk XPI
Install LibreOffice Integration Trunk XPI

Connector debug builds are identical to released connector versions, but include the automated translator testing tool accessible from the preferences. Because the testing tool imposes overhead on every page load, they are not recommended for everyday use.

Install Chrome Connector (Debug) 2.999.1
Install Safari Connector (Debug) 3.0b1

It is generally possible to switch back from a Zotero branch development XPI to the latest official branch release. Going back from a Zotero trunk development XPI to the latest official branch release is often not possible, and is not recommended. It is always possible to switch between development versions and official releases of the word processor plugins and Zotero connector (although the installed version has to be compatible with the installed version Zotero client).