Iris OS

Iris OS is a series of operating systems made by ecSoft (now iriSoft) in 1993. The latest version of Iris OS as of 2023 is Horizon, which modernized Onyx greatly with modern UI, features and more.

ecOS

 * ecOS 1 (1993)
 * ecOS 2 (1995)
 * ecOS 3 (1998)
 * ecOS 4 (2000)
 * ecOS NEXT (2003)
 * ecOS '07 (2007)
 * ecOS Eco Edition (original name, 2009)
 * ecOS '12 (2012)
 * ecOS '14 (2014)
 * ecOS '16 (original name, 2016)

Iris OS

 * Iris OS Onyx (2019)
 * Iris OS Horizon (2023)

1990's - the start
In 1991, development of iriSoft's own operating system was started. It was later released in 1993 as the very first version of Iris OS. The OS was later pre-installed on all iriSoft-brand computers as an optional configuration since 1993.

Trivia

 * After Iris OS '16, OS codenames would be named after cities in the US west coast.
 * Early versions of ecOS NEXT used the older ecOS kernel before switching to the modern Cornea kernel in the public betas.