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As I understand it, the LaTeX ecosystem has been gradually inching toward PDF as the default output format for a while. However, DVI is indispensable for a workflow I've been experimenting with to produce compact, high-quality SVGs from LaTeX, namely using dvisvgm (even though dvisvgm can also convert PDFs to SVGs, this process supports less features than DVI-to-SVG conversion). After seeing several questions and answers on this site asking if- or declaring that DVI is obsolete, I got worried about whether this format was "on its way out". Since these matters are often very subjective, I figured that there was one way I could definitely reassure myself that DVI was here to stay: if LuaLaTeX and pdfLaTeX (both capable of producing DVI) still use DVI as an intermediate format for their production of PDFs (e.g., via dvipdf), then DVI's perseverance was assured.

Accordingly, I ask my titular question: Is DVI used as an intermediate format by pdfLaTeX and LuaLaTeX? Or do these engines have wholly separate implementations for .tex → DVI and .tex → PDF compilations? Or something in-between?

PS: I'm aware that XeTeX relies on XDV, an extension of DVI, as an intermediate file format.
PS2: I do not mean to imply with this question that there aren't plenty of other uses for the DVI file format.

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    PDFTeX and LuaTeX engines have two internal backends for DVI and PDF. DVI is not used as an intermediate format for PDF. This is a difference to XeTeX.
    – cabohah
    Commented May 28 at 17:59
  • @cabohah In that case, what are the reasons that the maintainers of these engines might use to motivate their work on the DVI backend given that PDF output is presumably much more prevalent? Or is it somehow not as much work to maintain two separate backends (as opposed to a single backend) as I imagine?
    – steve
    Commented May 28 at 18:05
  • @steve What work are you imagining? Very little is added to either pdfTeX or LuaTeX - some very focussed stuff to support tagging, mainly
    – Joseph Wright
    Commented May 28 at 18:07
  • @JosephWright I assumed that the continued maintenance of the engines was a major undertaking, simply because it's a large piece of software dealing with lots of low-level details, often pertaining to evolving standards. But I'm very glad to be wrong here
    – steve
    Commented May 28 at 18:15
  • @steve Making sure they still compile is non-trivial, but DVI vs PDF makes only very limited impact on that
    – Joseph Wright
    Commented May 28 at 20:05

2 Answers 2

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No: in PDF mode both pdfTeX and LuaTeX generate PDFs directly. However, both engines are well supported and stable, and as far as anyone can say will continue to be available in the long term. As such, generating DVI output will continue to be possible.

(Note that LuaMetaTeX, which is effectively LuaTeX 2.0, doesn't even have a built-in backend for PDF - all output is sorted by coding the backend separately from the engine.)


On whether the format is 'on it's way out', whilst the engines will continue to support DVI, for making PDFs there are some things that only work completely smoothly in direct PDF mode. As such, for many users, DVI mode is not something they necessarily need.

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No pdftex (and luatex) have two separate backends built in, they generate either DVI or PDF, but one or the other, the PDF is not generated by transforming the DVI.

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