Actually most of them are useful, I'll try to order them by importance/usefulness (IMHO, of course):

1. indent_style, indent_size, tab_width (as mentioned above, indent_style = spaces is still useful with indent_size because then you can correctly edit files in diff view, too)
2. charset (this would be godsend, currently I have to restart SmartGit with JAVA_TOOL_OPTIONS=-Dfile.encoding=<encoding> every time I need to work with some non-UTF8 source code (yes, such files still exist ;-))
3. trim_trailing_whitespace, insert_final_newline
4. end_of_line (this is perhaps implicitly done)

Hi Daniel,

not sure what exactly do you have in mind. :-)

I use Linux + Kate as an editor (usually) for editing various open source projects. Very often a few at the same time (e.g. a project which requires SDL_mixer usually involves messing with the project, SDL and SDL_mixer at the same time) and as it goes, each of them has separate tab/space/indent conventions.

It's easy to switch between the projects (repositories) in SmartGit but when I bump into the issue mentioned - sometimes I need tabs + indent size 2, sometimes spaces + indent size 4 (although here it matters only if I want to edit something withing the diff editor of course) etc. Very frustrating.

When I discovered .editorconfig, all my issues went away, well, except when working with SmartGit. :-)

(don't get me wrong, I love it, I'm using it for more than 10+ years and paid for it for my commercial activities, too)