EditArea : http://sourceforge.net/projects/editarea

特点：

1. 一个 Javascript 编写的代码编辑器, 支持代码加亮, 缩进, 行号等特征;

2. A free javascript editor for source code. It allow to write well formated source code with line numerotation, tab support, search & replace (with regexp) and live syntax highlighting (customizable).

3. 一个实际的例子: http://www.cdolivet.net/editarea/editarea/exemples/exemple_full.html