Identify this famous pair.

The title was a hint asking you to see properly :) Many people missed a subtle difference.

Cracked by: jayanth , bs , srichand , nihit , Abhishek , shyam , Sandesh , ram , alephnull , Prasad , yaksha , Ganesh Prasad , srikanth , Shashank

Ken Thompson and Dennis Ritchie.
Many people thought it was Brian Kernighan and Ritchie… well, near but not right :)

jayanth, bs, srichand, nihit, Abhishek, shyam, Sandesh, ram, alephnull, Prasad, yaksha, Ganesh Prasad and Shashank