libjs-edit-area

a free javascript editor for source code
Edit-area is a free javascript editor for source code that is easy to
integrate, has only one script include and one function call. It supports
tabulation (allow to write well formated source code), has customizable
real-time syntax highlighting (currently: PHP, CSS, Javascript, Python, HTML,
XML, VB, C, CPP, SQL, Pascal, Basic, Brainf*ck, and probably more...),
word-wrap support, search and replace (with regexp), auto-indenting new
lines, line numerotation, multilanguage support (currently: Croatian, Czech,
Danish, Dutch, English, Esperanto, French, German, Italian, Japanese,
Macedonian, Polish, Portuguese, Russian, Slovak, Spanish, and probably
more...), has the possibility to use PHP gzip compression (compress the 12
core files to one file of ~30Ko), allows multiple instances, has a full
screen mode, possible plugin integration, possible save and load callback
functions, possible dynamic content management, can work in the same
environment than prototype and mootools's like libraries.