Haidoku is a Chrome add-on developed by Ryosuke Ohta. It allows users to display the contents of Wiktionary and Wikipedia directly in their browser window. This feature is particularly useful for those studying languages, as it enables them to read websites while accessing dictionaries and search links.

The Haidoku widget appears when text is selected, providing quick access to dictionaries and search options. Users can choose to display Wiktionary and Wikipedia contents, as well as search links such as Google and Cambridge Dictionary. The add-on also offers various settings, including the ability to execute in specific domains, edit links, view history, and customize the widget layout. Additionally, users can change the languages of Wiktionary and Wikipedia to suit their needs.

For more information on the latest release and announcements, users can visit the official GitHub page and Twitter account respectively. Any feedback, bug reports, suggestions, or questions can be submitted through the GitHub issues page.

Please note that personal contact information for the developer, Ryosuke Ohta, in Tokyo, Japan, is provided for reference purposes only and should not be used for direct contact.