HyperKitty

HyperKitty is the official web archiver for the Mailman 3 mailing list management system. It replaces the older Pipermail and gives list archives a modern interface. You can browse messages by thread, date, or author, and it includes a full-text search engine powered by Whoosh or Elasticsearch. HyperKitty also tracks statistics like top posters and busiest threads.

HyperKitty integrates tightly with Django, the Python web framework, and uses either PostgreSQL, MySQL, or SQLite as its database backend. It supports Gravatar and Libravatar for user avatars and includes a REST API for external integrations. The archiver can also crosspost messages across lists and handle multiple domains. HyperKitty is open source under the GPLv3 and maintained by the GNU Mailman project.

This tool is ideal for communities or organizations running Mailman 3 who want a modern, searchable archive. It works on Linux and other Unix-like systems and requires Python 3.6 or newer. HyperKitty is production-ready and is used by major open source projects for their mailing list archives.