"Apache 1.3 was ported to a variety of platforms, including many that weren’t POSIX based, such as Windows, OS/2, and BeOS. On those platforms, Apache 1.3 often relied on #ifdef blocks to acheive portability, effectively forking the source into mainline code and platform-specific code, making the code harder to read, debug, and maintain.
"When development started on Apache 2.0, the developers knew that they needed a better solution. Initially, two existing solutions were considered. One was the Adaptive Communication Environment (ACE), and the other was the Netscape Portability Runtime (NSPR). However, both were rejected..."
