YY-CHR
YY-CHR is a proprietary Windows CHR editor by a Japanese Super Mario Bros. hacker named YY, with many features and for multiple consoles and handhelds.
It used to be a HSP (Hot Soup Processor) program, but due to false virus warnings, it has moved to C++ and later C# with .NET support.
The latest version of YY-CHR can be downloaded from the YY-CHR @wiki.
Old versions v0.99 or under can be found in the Outdated tools section.