ASCIIMathML.js is freely available under the GNU General Public License. The current version is 1.4.7 (what's new).
It is very easy to use ASCIIMathML.js on your own webpages. If you use it on a webpage, please put a link to www.chapman.edu/~jipsen/asciimath.html on that webpage and send me an email at firstname.lastname@example.org with the URL so that I can add a link on the users page. (Also send me an email if you have problems or would like to provide some feedback.)
To write your own HTML file that uses ASCIIMathML.js, save your file with the standard .html extension and just load the ASCIIMathML.js script in the head of your HTML file. More explicitly, use the following lines at the top of your file:
Note that ASCIIMathML.js should be in the same folder as your HTML file (alternatively include the full path to ASCIIMathML in the 3rd line above).That's it!
Here is a sample file that you can save and modify to suit your local needs. Right-click on the file and use Save Target As... to save this file (if you choose Save As ... while viewing the file, IE does not save the correct header information). Check that the HTML file is viewable by IE+MathPlayer and by Netscape7.1 (or equivalent).
Note that usually Netscape7/Mozilla/Firefox do not display MathML in HTML files (only in XHTML files), but with ASCIIMathML they do!
Here is some information on how to extend ASCIIMathML.js with additional symbols (this method may be preferable to editing the file ASCIIMathML.js).