Can you make valid Makefiles without tab characters?

Question

target: dependencies
    command1
    command2

On my system (Mac OS X), make seems to require that that Makefiles have a tab character

Answer 1

in ubuntu: vi Makefiles replace space by tab (or anything else you want):

:%s//^I/g

For ex replace 8 spaces by tab:

:%s/        /^I/g

Be attention: ^I insert with tab key, not ^ and I characters :D