-## What is this?
-
-It's several things.
-
-First, it's a usable libc. It builds a "sysroot" which can be pointed to by
-compilers, such as Clang 8.0, using the wasm32-wasi target. It's a work in
-progress, but it is already sufficient to run basic programs.
-
-Second, it's a "reference" implementation, which means the interfaces defined
-here can be used by other tools and libraries, even if they don't use all the
-actual implementations here. For example, we don't expect everyone will want
-to use the exact `malloc` implementation provided here, but tools and
-libraries using an ABI-compatible `malloc` interface will be able to
-interoperate regardless of which actual implementation is used.
-
-Third, it's an example showing the use of the WASI API. The libc functionality
-is implemented using calls to WASI functions.
+WASI Libc is sufficiently stable and usable for many purposes, as most of the
+POSIX-compatible APIs are stable, though it is continuing to evolve to better
+align with wasm and WASI. For example, pthread support is still a work in
+progress.