I noticed that version 0.00 of luatex could print back TeX. Is that still possible? If not how difficult would it be to implement, and where would I begin? Could it be done entirely with lua, or would I have to change luatex itself? I admit I haven't looked into it very much because I wanted to know if it was feasible before I started since I have never looked at the TeX codebase. I would like it for two quite different reasons. 1. I would like to make an optimized TeX file that will create a dvi very quickly on an embedded device (a la http://river-valley.tv/tex-as-an-ebook-reader-2/) 2. A more useful, though difficult, option would be to mark certain macros, (or those from certain files, etc.) as "expandable", and everything else would be literally passed through (ideally comments as well). This would allow a person to use their own macros, but create a "standard" (La,Con)TeX file when sharing with a colleague or submitting to a journal etc. I know other people that have expressed in the latter usage, though it is obviously quite a bit more complex. Thanks for any pointers, Ivan Andrus