Why It Matters

Without this exception, using LLVM-compiled code or linking LLVM runtimes could create legal uncertainty for:

• Proprietary software that needs to ship binaries
• GPL-licensed software, since Apache 2.0 and GPL v2 are otherwise incompatible
• Any project worried about patent risk propagating through the toolchain

In Short

The LLVM Exception makes LLVM safe to use as a compiler and runtime toolchain without the Apache 2.0 license's conditions "infecting" the software you build with it. It's a practical legal workaround to ensure LLVM can be widely adopted without licensing friction.