TEX was originally written in Pascal, then rewritten using Knuth's WEB system, from which a Pascal program can be built. Due to the general lack of Pascal compilers for Unix, early versions for Unix were written from scratch in C, and several of these have been ported to OS9. More recently, a program to translate Pascal to C has been used to port the newest WEB sources to Unix and other systems. My OS9 port started with this translator program, which has allowed me to compile the most recent versions of TEX, MetaFont, and other TEX software under OS9. I have also ported the suite of DVI translator programs maintained by Nelson Beebe at the University of Utah. These include translators for several popular dot-matrix printers and the more common laser printers.
Unfortunately, the newer versions of virtex and initex do require substantial amounts of memory. On my 3-megabyte MM/1, I have found that the largest free block of memory needs to be in excess of 1500k in order to run initex. Fortunately, the other programs are somewhat leaner; virtex requires 1400k, inimf and bibtex each require 800k, and the various DVI translators require from 100k to 600k depending on the printer and the document. Many users may be forced to use one of the older versions of initex and virtex due to memory constraints.