What you call "legitimate use" of '\\' in Unix-like environments is a convention effected by shells, compilers, and many utility programs. At the API and executable machine code level, no such distinction has to be made on the modern Windows platform (at least not until the path parsing occurs.) Unixen are not agnostic as to path separator, but the Win32 APIs are. True, many Windows applications get fussy about it (including the SQLite library, apparently), but a call into the Win32 file access and management APIs will succeed independent of which path component separator, '/' or '\\' is used. When you say "Windows didn't seem to like it" when you typed "foo/bar.txt", you are referring to the behavior of some program which accepted typing, not the Win32 API. Moreover, it was a program getting needlessly disturbed about something which mattered on DOS but no longer matters on any Windows released in the last 20 years. Way too much programmer time is spent sniffing at user-provided paths before simply submitting them.