The Apache project is an effort to develop and maintain an open-source HTTP server for various modern desktop and server operating systems, such as UNIX and Windows NT. At present, the Windows version of Apache is not as stable as the UNIX version. Further releases are expected to bring it closer to parity.
Core enhancements in the new version include:
- Dynamic Shared Object (DSO) support where Apache modules may now be loaded at runtime. This means that modules can be loaded into the server process space only when necessary, thus overall memory usage by Apache will be significantly reduced.
- Apache now experimentally supports the Windows NT and Windows 95 operating systems.
- The source files for Apache have been re-organized. The main difference for Apache users is that the "Module" lines in Configuration have been replaced with "AddModule" with a slightly different syntax. For module authors there are some changes designed to make it easier for users to add their module.
- On almost all Unix architectures Apache now implements "reliable" piped logs where reliable means that if the logging child dies for whatever reason, Apache will recover and respawn it without having to restart the entire server.
More information is available here.