I've been working on an ANSI art editor off and on for a while. It works like a traditional ANSI text editor, except it supports 256 colors, Unicode and CP437 encoding, frame-based animation, custom UI themes, terminal mouse input, HTML and IRC color output, and runs in Utf-8 terminals.
It's written in Python and curses, and is fairly portable across Unix systems. If you have ever used TheDraw or Aciddraw, the user interface is similar. It can also load/convert, view, edit and save most CP437 (MS-DOS style) ANSI art in a Utf-8 terminal, so you can view ANSI artscene packs in the comfort of your favorite terminal, and even convert them into 256 color Unicode ANSI.
I've been using it for my own ANSI and ASCII art for a number of years, and hope this will help artists work with less restrictions. I think there is a lot of opportunity for ANSI art beyond its dominant 16-color Code Page 437 format. We all have computers with amazing ANSI terminals with modern features. Shouldn't they be the natural home for making text art?
It's still a work in progress, and I'm always adding features. Thanks for checking it out!