Vix is an experimental Vi clone. It probably isn't something in which you are interested yet. I am a big fan of Bram Moolenaar's Vim, and use it for my day-to-day programming work. I highly suggest you start there if you are looking for an excellent Vi clone.
To build vix, you will need a relatively recent version of Clang, Google Test, Haskell (ghc running under Haskell Platform is best supported), and shake. The current build assumes that it is built as part of a Google repo / submodule, and that Google Test is located under ../gtest. Since vix is the support library for the editor, it assumes that it is part of a larger project or tarball.