NOTE

As you may have noticed, asciiTeX is not maintained. There are two alternatives you may use. I saw somebody forked and updated asciiTeX here:
https://github.com/larseggert/asciiTeX

I myself have built a completely new code for monospace TeX-like math formatting. It supports unicode/utf-8 and has supports much more TeX syntax. The new system provides a little asciiTeX-like utility called utftex. It is built on top of a library, libtexprintf, which provides printf-like routines to pretty-print math. Check it out here:
https://github.com/bartp5/libtexprintf

asciiTeX

asciiTeX is an ASCII equation renderer released under the terms of the GNU General Public License. The program can generate ASCII-art representations of mathematical equations. You can use asciiTeX to quickly insert equations in e.g. e-mails or comments in your source-code. The syntax is similar to LaTex. The asciiTeX project is a fork of eqascii, providing new features and many bug fixes to the original program.

Features

Showcase

Before going into the gory details of where to obtain asciiTeX and asciiTeX operation, here are some examples of asciiTeX output.

asciiTeX does matrices,
 _         _  
| x     x   | 
|  11    12 | 
|           | 
| x     x   | 
|_ 21    22_| 

and things like this,
         /   1                       
         | -----  + 12      -120  

, and
  _                 _                                                 
 /  W  np          /  W                     n0                        
 |    -----dx  =   |    -------------------------------------------dx =
_/  0 n + p       _/  0     / E0(x - x0) \       /    E0(x - x0)\     
                        exp | ---------- | + exp |  - ----------|     
                            \     kT     /       \        kT    /     
                                                                      
              _                               _                       
             |         /      _          _  \  |                      
        n0kT |         |     | E0(x - x0) | |  |x = W      n0kT       
        ---- |  arctan | exp | ---------- | |  |         ~ ---- pi    
         E0  |_        \     |_    kT    _| / _|x = 0       E0        
, etc.

Download

Install

Compile from source (all systems)

To compile and install the program run
./configure
make
make install

This installs both the commandline utility aswell as the graphical user interface. If you do not wish to install the graphical user interface you can configure with the option --disable-gtk

Windows

An installer is available which installs the graphical version of the program.

Usage

asciiTeX_gui

Here are some screens:
screen 1 screen 2 screen 3
To run the GTK version of asciiTeX run asciiTeX_gui. A window apears with an
Equation Input Field
This is where you can edit your equation. See the description of the syntax below.
Equation Output Field
This is where the result is displayed (and can be copied from).
Generate button
Press this button to render your equation in ASCII.
Line-width check button
Turn on or off automatic line-breaking for long equations. This will cause asciiTeX to attempts to format the equation within the specified line width, i.e., asciiTeX will insert line breaks in order to format long equations over several lines. Note that this is not guaranteed to work, some equations cannot easily be formatted over several lines. See the Line-width Input Field.
Line-width Input Field
Here you can set the line-width in characters, see the Line-width check button.

asciiTeX

The command-line version of asciiTeX is simply called asciiTeX. To run use:
asciiTeX [-v] [-h] [-f file] [-ll line-length] [equation]

Options

-v
Print out the version of the asciiTeX executable and exit.

-h
Print out the version of the asciiTeX executable and exit.

-f file
This option specifies the equation should be read from a file (per default asciiTeX expects the equation on the command line).

-ll line-length
With this option asciiTeX attempts to format the equation within the specified line width, i.e., asciiTeX will insert line breaks in order to format long equations over several lines. The default is line-length 80 characters. With a specified line width of 0 asciiTeX will not insert line breaks.

equation
If the -f option is not specified the equation is read from the command line.

Syntax

asciiTeX implements a LaTeX style syntax to format equations.
Accepted syntax:
\frac{a}{b}
A fraction of a and b.
a^{b}
A superscript. One can also omit the braces. In this case the first character following ^ will be superscripted.
a_{b}
A subscript. Works just like the superscript (well, not exactly of course).
\sqrt[n]{a}
A n-th root of a, the argument [n] is optional. Without it it produces the square root of a.
\sum
Expands to a sigma.
\prod
Expands to the product mark (pi).
\int
Expands to the integral mark.
\oint
A closed path integral.
\left( , \right)
Expands to braces which adept to the height of their content. Available left braces are: ([{| The corresponding right braces are: )]}| All brace types can be opened by \left. or closed by \right. , producing a single right or left brace, receptively.
\leadsto
Expands to an arrow (~>) (may look ugly in some fonts).
\to
Expands to an arrow (->).
\limit{x}
Expands to a limit, i.e. \limit{x \to 0}.
\overline{X}
Draws a line above expression X
\underline{X}
Draws a line under expression X
\lceil
Left ceiling symbol
\rceil
Right ceiling symbol
\lfloor
Left floor symbol
\rfloor
Right floor symbol
\\
Insert a line break.
\begin{array}[pos]{column alignments}
a00 & a01 & ... a0n \\
a10 & a11 & ... a1n \\
... & ... & ... ... \\
am0 & am1 & ... amn
\end{array}
Makes an array. The optional argument pos sets the alignment of the array to t(op), b(ottom) or c(enter). The column alignments consist of one character per column, l(eft), c(enter), or r(ight). Currently asciiTeX does not support vertical or horizontal lines, e.g. the column alignment specification "{|c|}" will lead to errors. Note, that the string \begin{array} must not contain spaces. The cells inside an array may contain mathematical formulas and sub-arrays.
\a
Escapes the character a. Useful for inserting characters like ^, and _ in your equation.

Examples

A simple fraction:
asciiTeX "\frac{1}{1+x}"
1 ----- 1 + x

An arbitrary equation:
asciiTeX "\lfloorx\rfloor = x -\frac{1}{2} + \sum_{k=1}^{\infty}\frac{sin(2 Pi k x)}{pi k}"
1 __ oo sin(2 Pi k x) |_x_| = x - - + \ ------------- 2 /__ k=1 pi k
More examples can be found in the file "EXAMPLES" included in the download
asciiTeX -f EXAMPLES

Authors

The maintainer of asciiTeX is Bart Pieters (contact via this link) The program is a fork of eqascii which was written by Przemek Borys.