The wikipedia articles have more details on the history and. Luatex forked xetex and added a lua interpreter that makes it easier to. On some systems gcc behaves in the same way, compiling c if it is called as gcc. Unfortunately it does not produce pdf directly, but xdvi files which it then converts to pdf for the user. The reason that you need to know is that the set of functions available in each engine is different. It has been designed by parts of the pdftex team as the dedicated successor of pdftex, the current standard engine. Nontraditional research output software implementing pdf standards for mathematical publishing.
System runs linux mint, with emacs and the auctex plugin. When someone says tex cant find my fonts, they usually mean an engine. If you run latex or tex then you will get a dvi file which you can turn into a postscript file or a pdf, but if you run pdflatex you will get a pdf directly. E tex pdftex xtex luatex plain tex none etex pdftex none xetex dviluatex luatex latex none none latex pdflatex none xelatex dvilualatex. In exchange for this downside though, pdftex adds support for. The fontspec package requires either xetex or luatex.
Later in the project some functionality of aleph clarification needed was included esp. However as a descendant of pdftex it has the advantage that it generates pdf. Luatex is a new tex typesetting engine that fully supports unicode and modern font technologies such as opentype. For the sake of accuracy, it is important to note that although we described luatex as derived from pdftex, luatex does not directly use pdftex. Latex, plain tex, these are the texbased languages in which one actually writes documents.
Xelatex and luatex so far we have seen that tex has evolved in two different ways since its beginning. You do not expect a c compiler to work with java, do you. Luatex is a texbased computer typesetting system which started as a version of pdftex with a lua scripting engine embedded. Use this tag if the engine you employ pdftex pdflatex is significant to your question. Like knuths tex, it does not directly produce pdf output but rather. The luatex projects main objective is to provide an open and configurable variant of tex while at the same time offering downward compatibility. If there is no lua option, the commandline is interpreted in a similar fashion as in traditional pdftex. Merge the aleph and pdftex codebase so that luatex in dvi mode behaves like aleph, and in pdf mode like pdf etex.
After some experiments it was adopted by the pdftex team as a successor to pdftex itself an extension of etex, which generates pdfs. Pdftex and xetex and the equivalent commands for latex are two implementations for the same purpose, as you have pointed out already. Luatex is an extended version of pdftex using lua as an embedded scripting language. Luatex also adds many new primitive commands which provide control over the new features. When the luatex executable starts, it looks for the lua commandline option. Luatex is an extended version of pdftex with unicode and opentype font support, embedded lua scripting language, the etex and omega extensions, as well as integrated metapost engine, that can create pdf. Tex engine command line options for pdftex, xetex and luatex. In contrast, the engines xetex and luatex are both unicodebased and. As such, it remains an 8bit system using specialist font metrics. For example, pdftex implements direct pdf output which is not in knuths original tex, luatex provides access to many internals via the embedded lua language, etc.
Besides supporting a lua interpreter, luatex brings to pdftex quite the same. Tex engine command line options for pdftex, xetex and luatex pdftex version 1. Derived from pdftex but does not use pdftex s code. You often need to know what engine your macros are running on the engine is the texderivative or texalike processor that typesets your document. Note that in practice pdftex and pdflatex are often the same command, which analyzes how it was called to switch to the proper input language. No need to output a dvi and then convert into postscript. Thanh decided to create pdftex which outputs a pdf file from a tex document. Xetex modernised pdftex and added the ability to load system fonts. The field moddate indicates the modification date, and as with the creation date, the date should be entered in the form d. Xelatex and luatex so far we have seen that tex has. All current free t e x distributions including t e x live, mac t e x and mik t e x include pdf t e x plain t e x and pdf. With the addition of easier to use commands on top of the original system latex, and with. In the first part of this article, an introduction to luatex part 1.