&gt; - Performance. Other compiler backends often produce more efficient code than LLVM<p>I wouldn&#x27;t say &quot;often&quot; here. LLVM&#x27;s compiler backend is top-notch and is hard to beat. Often it comes down to random register allocation or scheduling differences.<p>&gt; - Windows support for LLVM is still not up to par yet. Supposedly it will be in the near future.<p>What are you referring to in particular? The only thing I can really think of is exception handling, and that got overhauled recently for MSVC compatibility. PDB was an issue too, but that&#x27;s gotten fixed and now LLVM can output PDB. I can&#x27;t think of much that&#x27;s left...<p>&gt; - You can distribute the C output from your compiler, and others can use it without having to work your compiler into their build process.<p>That is a legitimate advantage. But on the whole I think that it&#x27;s outweighed by the downsides of compiling to C.