🚀 go-pugleaf

I am looking for product information about language-based editors.
The editor I am looking for should support the following functionality:

- It must support more than one computer language, preferably ALL
  structured text.
- It must be available at more than one operating system, preferably
  UNIX, VMS and MS-DOS, or the source should be available.
- It should edit language-elements like statements/-parts instead of
  characters/lines/etc.
- It should be a WYSIWYG-editor.

I only know of one such product: The Synthesizer Generator from the
Cornell University. 

"The synthesizer Generator creates a language-specific editor from an
 input-specification that defines a language's abstract syntax, context
 sensitive relationships,..."

I have two questions:

1. How and where can I order this Synthesizer Generator?
2. Are there any similar products available?

Thanks in advance.
-- 
Marco Luiten