It is true that unit testing lacks some of the accessibility of a diagram, but UML diagrams are now easily generated for most modern languages by free tools (usually available as extensions to IDEs).
Central processing unit | Law & Order: Special Victims Unit | The Unit | Larissa (regional unit) | Economist Intelligence Unit | Diesel multiple unit | central processing unit | Company (military unit) | UNIT | unit | Chania (regional unit) | mya (unit) | Educational Testing Service | diesel multiple unit | Trikala (regional unit) | G-Unit | Air Force Outstanding Unit Award | Navy Unit Commendation | Kastoria (regional unit) | Rethymno (regional unit) | Genetic testing | 22nd Marine Expeditionary Unit | University Royal Naval Unit | Special Victims Unit | Meritorious Unit Commendation | memory management unit | Engine control unit | engine control unit | company (military unit) | Beverage Testing Institute |
; Cactus:Cactus was a simple test framework for unit testing server-side Java code (Servlets, EJBs, Tag libs, ...) from the Jakarta Project.