itrans can accept TEX input and generate TEX output for all languages for which either a PostScript font description or a Metafont description is available. At the time of this writing, both devanagari and tamil are supported through this interface.
For example, the aa character in the table in the document dvnc.itx was produced by this input text:
{\char92marathi aa \char92endmarathi}
Thus, the character aa, when bracketed between \char92marathi and
\char92endmarathi produces aa, when the appropriate IFM file
name and font command name have been set correctly (as mentioned in the
previous section).
For further examples, see the sample documents provided. All TEX transliterated files have been given the file extension .itx.
Normally, all english text between the words \char92marathi and \char92endmarathi is mapped into
marathi characters, except for the word following a backslash character.
I.e., you can include TEX commands in the transliterated text
portion, the only restriction is that the command should be made up of
letters and numerals only.
Examples: \indent or \hskip1in or \kern0.4em, etc.
Note that in the sample documents shown, TEX commands are usually
surrounded by curly braces—they used as scope delimiters only, are not
absolutely necessary, but are recommended.