My impression (as someone working on a compiler of my own, using LLVM), is that while you get a lot out of building on LLVM (portability across platforms, a col

My impression (as someone working on a compiler of my own, using LLVM), is that while you get a lot out of building on LLVM (portability across platforms, a collection of "free" optimizations, and a well defined low-level IR), it comes at the cost of a huge toolchain (takes about 5-10 minutes to compile from scratch on my laptop), and it is not stable across releases (the extent to which you are affected depends on the features your compiler depends on though). I think for toy projects it is probably more interesting to write the code gen yourself; and for projects focused on a specific platform, it is perhaps desirable to handle it yourself. Some people probably just don't want the dependency. My perspective is that I don't want to reinvent the work on cross platform support, or the optimization passes, and would rather take advantage of those efforts by depending on LLVM. I don't know that this makes sense for this project though.