Since Babelized software must be built the same way that Babel itself was configured, it seems reasonable to lean on babel-config quite heavily. By now you are probably wondering how many secrets babel-config holds and can provide on request. The simplest way to find out is to ask it. (Though you may get a slightly different result than what is shown here depending on the version of Babel.)
% babel-config -dump-vars | wc -l
128
babel-config can provide a wealth of information determined by Babel during its configuration and installation. Even if you do not use the GNUmakefile's that Babel can generate, you will likely end up using babel-config to determine important information about Babel's installation