GCC
Software / App
A widely used C++ compiler that improved significantly due to competition from Clang.
Mentioned in 2 videos
Videos Mentioning GCC

Chris Lattner: Compilers, LLVM, Swift, TPU, and ML Accelerators | Lex Fridman Podcast #21
Lex Fridman
A widely used compiler at the time Clang was developed; Clang aimed to improve upon aspects like error messages and research utility.

Bjarne Stroustrup: C++ | Lex Fridman Podcast #48
Lex Fridman
A widely used C++ compiler that improved significantly due to competition from Clang.