LLVM used GCC C as a front end. Clang was an Apple project, since GCC wasn't designed to integrate into an IDE like Xcode.
>One of Clang's main goals is to provide a library-based architecture, so that the compiler could interoperate with other tools that interact with source code, such as integrated development environments (IDE). In contrast, GCC works in a compile-link-debug workflow; integrating it with other tools is not always easy. For instance, GCC uses a step called fold that is key to the overall compile process, which has the side effect of translating the code tree into a form that looks unlike the original source code. If an error is found during or after the fold step, it can be difficult to translate that back into one location in the original source.
I said it was created by him while he was at Apple:
> While it’s true that Lattner worked for Apple while he created Clang and that his personal contributions were probably biased
But it wasn’t silo’d into Apple and then released to the open source field, it was created as an open source project under the LLVM Developer Group from it’s inception.
So yes, his contributions and goals were to make it targeted for Apple’s needs; but there were plenty of independent contributors that were focused on just making it a good C/C++ compiler front-end for LLVM and were more focused on making it a general competitor to GCC.
It would be more accurate to refer to is as an Apple sponsored project.
>One of Clang's main goals is to provide a library-based architecture, so that the compiler could interoperate with other tools that interact with source code, such as integrated development environments (IDE). In contrast, GCC works in a compile-link-debug workflow; integrating it with other tools is not always easy. For instance, GCC uses a step called fold that is key to the overall compile process, which has the side effect of translating the code tree into a form that looks unlike the original source code. If an error is found during or after the fold step, it can be difficult to translate that back into one location in the original source.
https://en.wikipedia.org/wiki/Clang#Background
Lattner gave a tech talk at Google introducing LLVM 2.0 and explaining some of Apple's rational for creating Clang.
https://www.youtube.com/watch?v=VeRaLPupGks