Thanks, but as I said, I actually succeeded in compiling (on PPC), but my problem was the missing luatex.fmt
Sure, I was merely replying to Hans. To build the format, as he said, you must run LuaTeX in ini mode; so, to build, say, “plain LuaTeX”: ./luatex -ini --progname=luatex -jobname=luatex '\input plain.tex\dump' should build a format file with the name luatex.fmt, provided plain.tex is found by LuaTeX (I suggest putting it in the current directory for now). The problem you have here is that LuaTeX is not “distributed” with a set of TeX files, fonts, etc.; the only product is the binary, so you should make the distribution yourself. For my personal use, I chose to fake a real TeX installation by putting all the binaries in directories like $HOME/TeX/luatex/dev/$rev (with rev the number of the current revision; 508 as of this afternoon); and putting links from $HOME/TeX/luatex to the different texmf trees of the standard TeX Live installation (texmf, texmf-dist, texmf-var, etc.). This works because kpathsea expects to find the texmf trees either in the parent directory, or in the grand-parent. I find this architecture quite practical for all the different extensions of TeX currently under development (not only for LuaTeX). Once you have done that you can use LuaTeX pretty much like you use the original TeX or PDFTeX, with all the packages you wish (although I couldn't recommend trying to use LaTeX at this stage, mostly because of the hyphenation patterns). Arthur