The Eplain macro package expands on and extends the definitions in plain TeX. This manual describes the definitions that you, as either an author or a macro writer, might like to use. It doesn't discuss the implementation; see comments in the source code (xeplain.tex) for that.
Eplain is not intended to provide “generic” typesetting capabilities, as do LaTeX (written by Leslie Lamport) or Texinfo (written by Richard Stallman and others). Instead, it provides definitions that are intended to be useful regardless of the high-level commands that you use when you actually prepare your manuscript.
For example, Eplain does not have a command \section, which
would format section headings in an “appropriate” way, such as
LaTeX's \section. The philosophy of Eplain is
that some people will always need or want to go beyond the macro
designer's idea of “appropriate”. Such canned macros are
fine—as long as you are willing to accept the resulting output. If
you don't like the results, or if you are trying to match a different
format, you are out of luck.
On the other hand, almost everyone would like capabilities such as cross-referencing by labels, so that you don't have to put actual page numbers in the manuscript. The author of Eplain is not aware of any generally available macro packages that (1) do not force their typographic style on an author, and yet (2) provide such capabilities.
Besides such generic macros as cross-referencing, Eplain contains another set of definitions: ones that change the conventions of plain TeX's output. For example, math displays in TeX are, by default, centered. If you want your displays to come out left-justified, you have to plow through The TeXbook to find some way to do it, and then adapt the code to your own needs. Eplain tries to take care of the messy details of such things, while still leaving the detailed appearance of the output up to you.
Finally, numerous definitions turned out to be useful as Eplain was developed. They are also documented in this manual, on the chance that people writing other macros will be able to use them.
You can send bug reports or suggestions to
tex-eplain@tug.org. The current version number of Eplain is
defined as the macro \fmtversion
at the end of the source file eplain.tex. When corresponding,
please refer to it.
To get on this mailing list yourself, email tex-eplain-request@tug.org with a message whose body contains a line
subscribe you@your.preferred.address
or visit http://tug.org/mailman/listinfo/tex-eplain.
David Walden had reported his experience with Eplain as a new user. The article is available online at http://tug.org/pracjourn/2005-4/walden. An introductory article (written for TUGboat) is also available online at http://tug.org/eplain/misc/tb84katsi.pdf.