I want to create an open source text editor in which everyone can contribute in making it better...maybe there will be an OpenOffice for Amiga!!! .....maybe.
Since you mention OO, are you talking about a text editor or word processor?
Probably the most used pure Text Editor in the world right now was originally developed on the Amiga, and the author may be still compiling the latest versions on his old A2000: VIM, the VI iMproved editor. Most certainly open source, now has really large code base, and probably as difficult to contribute code to as the Linux kernel itself.
Then there is my favorite, also developed on the Amiga, also as portable as VIM, not nearly as powerful, but is about 5% as much code. It's called 'ne', for Nice Editor:
http://ne.dsi.unimi.it/It has text-mode drop-down menus that even work if you telnet into the Amiga, something that I found on no other Amiga editor. I use the latest version on all machines I work on, generally where others would use VIM, on Mac OS X, Unix, and Linux. However, I can't get the latest versions to compile on the Amiga, although I have not spent much time trying.
The older version is on Aminet that includes source and a SAS C makefile, the new source from the website, which still mentions Amiga! I would love to have the latest version of ne (back) on the Amiga!