Here is a collection of TeX converters that I have ported for the Macintosh (OS 9!). To compile the converters, it is necessary to use a framework called DropUnix. The compiled applications (as a fat binary) are available as well as source code and project files for CodeWarrior Pro 2. I made minor hacks in almost every case to get the code to compile and did not comment these changes. If you are interested in improving any of these programs I suggest you get the originals from CTAN and find the differences.

DropUnix has made the ports consistent and relatively easy. This allows one to drag a rtf file (for example) onto the rtflatex application and get it converted. The downside is that configuration options are reached in a bizarre way - namely that you must create a folder for each option you wish to alter. For example, to simulate the unix command rtflatex -s -r file.rtf one would create two folders one named "-s" (no quotes) and one named "-r" in the same location as file.rtf. Then the two folders and the file.rtf should be dragged onto the rtflatex application.

RTF to (La)TeX

I have five of these converters here. The only one you should even consider is rtf2latex2e. I will probably eliminate the others in the future.

rtflatex2e
by Ujwal Sathyam was written in C. This produces the cleanest LaTeX of any of the converters. It handles tables, figures and now equations! The current version is 1.0b4 (the large jump in equation numbering is the because equation translation has finally been included). I think that the version will continue to be "beta" until the documentation and packaging problems are largely fixed.
Visit the RTF2LaTeX2e web page to download the current version
rtf->latex
by Brian Jefferies was written in Pascal. I don't think that he ever released the source code. This program translates some equations very nicely from some RTF files and fails badly on others. The program tends to be slow.
Application
rtflatex
by Daniel Taupin and was originally a Pascal program. This was translated to C and that is the version (2.14) that I compiled. At one point I had the original Pascal version compiled, but somehow I lost that ability. Anyway, the real advantage of this program is that it processes embedded figures very nicely. It creates the separate files for each of the figures and produces latex commands so that the figures show up in the file. I don't know how well it works on Windows .wmf files, but Macintosh pict files work fine. This program does not do equations and I don't think that it does tables either. The C code is not very pretty and one must question how much this program might be improved without a lot of work. Oh yes, this program uses a file rtflatex.skw that lists RTF commands that it should ignore. This is pretty handy. The LaTeX code that this program produces is not very pretty but is pretty straightforward.
Application | Source
rtf2latex
by Erwin Wechtl is based on Paul DuBois's RTF translator package. I ported the code to CodeWarrior and omitted the ThinkC console interface. I don't think that this code works equations, tables, or figures. However, this program has options to ignore rulers setting and other frivolous formatting settings. This program is capable of producing the simplest LaTeX code. Oh, yes. This program requires a bunch of supporting files to be in the same folder as the rtf2latex application.
Application | Source
w2latex
by Javier Garmendia and Jean-Louis Maltret originated as a lex program (1994).
The version that I ported included a few fixes by Wilfried Hennings. w2latex handles equations. It doesn't seem to work so well with figures, but it certainly could be extended. I don't know about tables. The latex code that it produces is not particularly pretty, but it does have the advantage of not requiring a separate style file for the output to be LaTeXed. One annoying feature is that the documentation is in French.
Application | Source

(La)TeX to RTF

The latex2rtf sourceforge project has recent versions for Unix and Windows machines. This is the only place you really need to look for reasonably recent computers. I have not deleted the rest of this section because it might help someone.

These two applications are based on the same v1.5 latex2rtf source by Ralf Schlatterbeck. They evolved separately from each other. They have two philosophies about how to handle equations. latex2rtf simply translates equation codes into a near approximation of the LaTeX. This loses all the cool formatting, but provides an editable equation in the rtf document. ltx2rtf relies on a TeX implementation to create a bitmapped image of the equation that gets put in the RTF file. This functionality is missing from this Macintosh Classic port.

latex2rtf
Macintosh version 1.9b based on version 1.8a September 1999. I fixed many bugs and significantly improved how well it works on the Macintosh. For example, you can ignore the comment on the latex2rtf page because latex2rtf now just "does the right thing" with files from other platforms. I was really surprised when I ran the program recently on a document that contained a bunch of references. latex2rtf inserted all the correct figure and equation reference numbers and a formatted bibliography into the translated document (using the .aux file and .bbl files created by running latex and bibtex). This is now my preferred implementation. This version inserts .pict files that use the \includegraphics command.
Application and Source code
ltx2rtf
based on version 4.7 April 2000. This translator also does equations. Unfortunately, not in this port. Probably not ever because it requires the usual tex utilities (Metafont etc.) to create an image of the equation. However, ltx2rtf generally does a very nice job. Perhaps better that latex2rtf for some files. It does not attempt references and bibliographies. It also does not insert figures.
Application | Source
tex2rtf
by Julian Smart version 1.62. This works OK on very simple TeX files, but makes no attempt to convert math, figures or tables. It is written in C++ and was the most obnoxious program to port. It might work much better if some time was spent on the tex2rtf.ini file to define many common TeX macros.
Application | Source

TeX to ASCII

detex
by Daniel Trinkle version 2.4+. This works OK on very many TeX files, but makes no attempt to convert math, figures or tables. It is written in lex and was straightforward to port as soon as I found a recent lex plugin for CodeWarrior Pro 2. I have added quite a few more TeX commands to the lex file, but it is still far from complete.
Application | Source

Troff to TeX

tr2tex
was written C in 1987 Kamal Al-Yahya and updated in 1991,1992 Christian Engel. This program translates many troff commands, but doesn't do tables or equations.
Application | Source