Esperanto (formally Esperanto.4733) is a computer virus that appeared in 1997, named for the constructed language Esperanto. The program's name was derived from its cross-platform nature, with it being able to attack DOS, Windows, and Macintosh systems, being "international" in a similar way to Esperanto. The virus was the first platform-agnostic virus of its kind. The virus is also pays homage to the language in that it is activated on 26 July, Esperanto Day.

Design

Esperanto is capable of infecting both .COM and .exe files on PC, as well as most programs on Macintosh. Despite its platform neutrality, it appears as though it never spread organically across platforms due to recompile errors in the source code, and to cross platform barriers needed to be transferred through manual means. It ran entirely independently on each platform.

Esperanto lays unapparent when it spreads through infected files, but is activated on 26 July each year when infected programs are executed. This day is also known as Esperanto Day, the anniversary of the symbolic founding of the language. When an infected file is launched on 26 July, it will display the following bilingual text in English and Esperanto;

Due to the bilingualism of the messages, some have theorized that the virus programmer behind Esperanto.4733 may have been an Esperantist, and the program was made for the purpose of the promotion of Esperanto.