THINK C was an extension of ANSI C for Mac OS developed by THINK Technologies; although named Lightspeed C in the original mid-1986 release, it was later renamed THINK C. THINK Technologies was later acquired by Symantec Corporation and the product continued to be developed by the original author, Michael Kahl. Version 3 and subsequent versions were essentially a subset of C++ and supported basic object oriented programming concepts such as single inheritance as well as extensions to the C standard that conformed more closely to the requirements of Mac OS programming. After version 6, the OOP facilities were expanded to a full C++ implementation, and the product was rebranded Symantec C++ for versions 7 and 8, now under development by different authors.