History

The asciinema project was started by Marcin Kulik in 2011.

While Marcin had been playing with the idea of sharing terminal session recordings on the web since 2010, the working prototype of what eventually became asciinema came to life a bit later.

Initially, all components of asciinema - the recorder (aka CLI), the player, and the server - were developed as parts of a single Ruby on Rails codebase. The recorder was a simple, single-file Python program. The player was a single JavaScript file with an ad-hoc, incomplete parser for ANSI escape sequences, using jQuery to juggle the lines of a fake terminal view in a web browser. It was rough but worked well enough to deserve continued development.

The project was initially named "ascii.io". In March 2012, the ascii.io site was launched, providing free hosting for terminal session recordings made with the asciiio script (triple "i", omg!). The project was renamed to "asciinema" in September 2013 and published as asciinema package to PyPI around the same time.

In late 2014, the recorder was rewritten in Go, preserving the functionality of the previous versions while improving in some areas. The first release of the new codebase was 0.9.9, published in December 2014.

The same year, version 1.0 of the player came out, quickly followed by version 1.0 of the recorder, which was released in March 2015. These releases stabilized the first version of asciinema's recording file format, asciicast v1.

Version 1.2 of the recorder was the final version implemented in Go. For several reasons, it was reverted to the previous Python implementation. The new-old recorder was released in July 2016 as version 1.3, with all new features backported from the Go codebase.

The lack of a proper ANSI parser in the early versions of the asciinema player was an obstacle to timely bug fixes and more comprehensive terminal emulation. Therefore, in 2015, work started on implementing a new version of the player with a proper ANSI-compatible terminal parser embedded. The result was asciinema player 2.0, rewritten from scratch in ClojureScript, and released in January 2016.

In 2017, the asciinema server was rewritten in Elixir and Phoenix. Around the same time, it was also made more self-hosting-friendly, with updated installation docs and a simplified setup in containerized environments.

February 2018 marked the release of asciinema recorder 2.0, which introduced an improved recording file format, asciicast v2, among many new features.

Another milestone was achieved in May 2022 with the release of asciinema player 3.0, in which the terminal emulation part was implemented in Rust (as the avt library) and compiled to WebAssembly, resulting in a 4x smaller, 50x faster player.

Outside of asciinema's core components, a new, ultra-fast asciinema GIF generator, agg, was released in August 2022. The creation of agg was, to a degree, sparked by avt. In fact, avt has also been integrated into the asciinema server, where it's used for thumbnail generation and recording analysis since 2020.

The final version of the asciinema CLI 2.x line, 2.4, was released in October 2023. This was also the last version built with Python.

The upcoming 3.0 version of the CLI has been rewritten in Rust, introducing live terminal streaming. As of May 2024, the new version is in the release candidate stage.