Now we need to make some choices between TeX, LaTeX2e, LaTeX 3, ConTeXt(LuaTeX), LuaLaTeX, XeTeX, XeLaTeX and...
I don't specially like the syntax of L3 but recently I was impressed by very convincing examples with L3 and Lua so syntax or not it's perhaps a good thing to learn how to use L3 and how to program with Lua. But if I introduce some L3 code in my packages, I might create some problems for some users. Is it possible to mix L3 and Latex2e? Lua is a very big step... but lualatex seems to be very promising.
We need to use options in a package, we need to use keys... What are the packages that are recommended with each method?
I think that immobility is not a good thing and I must choose a direction, so my question is to ask what are the advantages and disadvantages of the different methods? (Sorry if my English is very rough!)