win32 programming

[Fabrice Popineau]

Can anybody enlight me about the availability of these functions
under various versions of windows :

FtpGetFile, HttpOpenRequest, InternetReadFile .

M$ does not tell us when these functions have been introduced; they
are located in wininet.dll. Is this dll available for all versions of Windows ?
Even those without any Internet Explorer or with an old version of it ?

My point is -- I may be wrong -- I have the impression that HTeX features
have introduced some instability in windvi (between 0.58 and 0.63);
I do not like very much to ship libwww together with windvi. I'm pretty
convinced that I can easily remove libwww, but in some occasions, 
HTeX may require to download a file.

Thanks for any hint,

Fabrice Popineau