# Why don't modern TeX variants support floating point?

I understand that, at the time when TeX was devised, no single standard for floating-point calculations was available. But these days, there's IEEE 754. Why doesn't any TeX variant support it?

Granted, there's LuaTeX, but IEEE 754 was popular long before that, so the question is justified.

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Backward compatibility. –  topskip Dec 5 '11 at 12:43
Personally, I would already be satisfied with 64bit integer arithmetic. –  Martin Scharrer Dec 5 '11 at 12:53
@Seamus: All plots in my thesis are pgfplots-powered. That uses a lot floating point arithmetic. –  Stefan Majewsky Dec 5 '11 at 13:19
When you consider the thinness and preciseness of lines a printer is capable of, coupled to the absorptive properties of paper diffusing the ink (or blurring of toner prior to laser treatment etc.), not to mention the resolution of the human eye, you should be satisfied with pgfplots and 64bit integers at @MartinScharrer says. ;) –  qubyte Dec 5 '11 at 15:12
Contrary to the preceding comments, I can think of situations in which floating-point numbers would come in handy. See tex.stackexchange.com/questions/112599/…, for instance. Note that Bruno Le Floch and the rest of the LaTeX3 team have plans to make LaTeX3 compliant with IEEE-754-2008. –  Jubobs May 31 '13 at 22:48