Why are all versions of Logtalk numbered 2.x?
The number “2” in the Logtalk version number refers to the second generation of the Logtalk language. Development of Logtalk 2.0 started on January 1998, with the first alpha release for registered users on July and the first public beta on October. The first stable version of Logtalk 2.0 was released on February 9, 1999.