When in doubt, follow the local style, and after that, Mozilla style.
Of course, here are some more specific links.
CSS Guidelines
Makefile/Build system guidelines
Universal Guidelines
(Not rules.)
- Indentation is two spaces. no tab characters.
- Variable names use camelCase
- Capitalize classnames
- URL and GUID, never Url or Guid
- No whitespace at the end of lines
- Try to keep line length under 80
- Text-files should be <LF> line endings
- Prefix Songbird code with "sb" where ever Mozilla uses "ns".
- Else gets its own line.
- make and copy should be on their own lines (yes, I'm joking).