Gemini (protocol)

Gemini is an

The Gemini project was started in June 2019 by Solderpunk. Additional work has been done by an informal community of users. According to Solderpunk's FAQ, Gemini is not intended to replace Gopher or HTTP, but to co-exist with them.[1] Much of the development happened on the Gemini mailing list until the list disappeared at the end of 2021 due to a hardware issue.^[2] The creation of the Usenet newsgroup comp.infosystems.gemini in October 2021 was the first new newsgroup in the Big Eight hierarchy in eight years.^[3]

Design

The Gemini specification defines both the Gemini protocol and a native file format for that protocol, analogous to HTML for HTTP, known as "gemtext". The design is inspired by Gopher, but with modernisation such as mandatory use of Transport Layer Security (TLS) for connections and a hypertext format as native content type.^[4]

The design is deliberately not easily extensible, in order to meet a project goal of simplicity.^[5]

Protocol

Gemini is designed within the framework of the Internet protocol suite and like HTTP/S, Gemini functions as a request–response protocol in the client–server computing model. A Gemini server should listen on TCP port 1965. A Gemini browser, for example, may be the client and an application running on a computer hosting a Gemini site may be the server. The client sends a Gemini request message to the server, and the server sends back a response message. Gemini uses a separate connection to the same server for every resource request.^[6]

Gemini mandates the use of TLS with privacy-related features and trust on first use (TOFU) verification being strongly suggested.^[7]

Gemini resources are identified and located on the network by

gemini://example.com/

20 text/gemini
# Example Title
Welcome to my Gemini capsule.
* Example list item
=> gemini://link.to/another/resource Link text

Gemtext format

Gemtext format is line-oriented and the first three characters of a line determine its type. The syntax includes markup for headlines, flat list items, pre-formatted text, quotes and link lines. As with HTTP hypertext, URIs are encoded as

"Geminispace" denotes the whole of the public resources that are published on the Internet by the Gemini community via the Gemini protocol. Thus, Gemini spans an alternative communication web, with hypertext documents, including hyperlinks to other resources easily accessible to the user.[1]

As of February 2023,^[update] Geminispace consists of around 2300 online known Gemini appearances ("capsules") identified by crawling over 490,000 URIs.^[8]

Software

The Gemini software list covers client, server, libraries, and tools.^[9]
Gemini-to-HTTP proxy server gateways such as Mozz.us can be used by web browsers lacking Gemini support.^[10]

See also

• Text-based web browser

References

External links

• Official website
• Project Gemini FAQ
• Gopher, Gemini, and the rise of the small Internet: Beyond the Web in Linux Magazine
• Mozz.us Gemini-to-HTTP proxy