CadEditor is a universal level editor and some romhacking tools for many different games for NES and SMD platform.
Some of them:

Chip & Dale 1-2, 
Darkwing Duck,
Duck Tales 1-2
MegaMan 3-5
Tale Spin
Little Mermaid
Jungle Book
Flintstones
Contra Hard Corps
Earth Worm Jim 1-2
Pitfall
etc.

There are more than 400 configs for 500 levels for more than 80 games.
Configs are simple C# files, and they have simple structure, so new games can be added with no problems.
Full list of supported games:
https://github.com/spiiin/CadEditor/blob/master/CadEditor/cad_editor_supported_games.txt

CadEditor can be built with Visual Studio or Mono, it can be run on Windows, Linux and MacOS platform.

More info
http://spiiin.github.io/CadEditor/
(russian version)

Patreon page of editor
https://www.patreon.com/CadEditor
Become a Patron!

Screenshots

Latest release
https://github.com/spiiin/CadEditor/releases

Project on itch.io
https://spiiin.itch.io/cadeditor