XKit

XKit is the name of a collection of open-source browser extensions and user scripts designed to enhance the Tumblr blogging platform. Developed by volunteers, XKit provides a modular set of features that extend Tumblr's built-in functionality, including user interface improvements, posting assistants, and content moderation tools. Because it is modular, users can enable or disable individual extensions to tailor their experience.

Originating in the early 2010s, XKit was distributed through community-hosted repositories where contributors publish updates and new modules. The extensions run in the browser and modify Tumblr’s front end on the client side. As a community project, the activity and maintenance of individual modules have varied over time, with some modules becoming inactive as Tumblr changed its interface, while others have been continued or forked by different developer groups.

XKit has been widely used by Tumblr users seeking customization and enhanced control over their dashboards and posting workflow. It is not affiliated with Tumblr, Inc. and users should be mindful that third-party extensions can be impacted by platform updates and may raise privacy or security concerns. The XKit project stands as an example of a user-driven extension ecosystem built around a social media platform.