The SASS, Less and Stylus compilers and CLI apps are all stable and full-featured, both Less and Stylus have a client-side compiler, and all three are supported

The SASS, Less and Stylus compilers and CLI apps are all stable and full-featured, both Less and Stylus have a client-side compiler, and all three are supported by various asset preprocessors. It'd be nice if one of them became the de-facto standard simply because they're all so similar anyway and having a clear go-to solution is always nice, but I don't think crappy toolchains are a real problem with these tools.