vB version question

[t3chb0y]

What is the difference with the 2.3.xx , 3.0.xx and 3.5.xx versions?

[Scott MacVicar]

2.3.x = legacy version from 2001
3.0.x = deprecated version from 2004 (Rewrite of vBulletin)
3.5.x = version from 2005 (Improvement of features within 3.0)

The higher the number the more features.