Apache 1.3 was released, although in rather a partial form, in July 1998. The Unix version was in good shape; the Win32 version of 1.3 was regarded by the Apache Group as essentially beta software.
The main problem with the Win32 version of Apache lies in its security, which must depend, in turn, on the security of the underlying operating system. Unfortunately, Win95 and its successors have no effective security worth mentioning. Windows NT has a large number of security features, but they are poorly documented, hard to understand, and have not been subjected to the decades of discussion, testing, and hacking that have forged Unix security into a fortress that can pretty well be relied upon.
In the view of the Apache development group, the Win32 version is useful for easy testing of a proposed web site. But if money is involved, you would be foolish not to transfer the site to Unix before exposure to the public and the Bad Guys.
We suggest that if you are working under Unix you go for Version 1.3.1 or later; if under Win32, go for the latest beta release and expect to ride some bumps.