The Apache HTTP Server, colloquially called Apache is the world's most used web server software. This comprehensive Reference Manual covers everything you need to know, incl.:
Using the Apache HTTP Server
Apache Virtual Host documentation
URL Rewriting Guide
Apache SSL/TLS Encryption
Guides, Tutorials, and HowTos
Platform-specific Notes
Apache HTTP Server and Supporting Programs
Apache Miscellaneous Documentation
Apache modules
Developer Documentation
As Apache HTTP Server became such a big project over the years, we had to split this reference manual in three parts that are three separate physical books. To keep it consistent with the digital manual, the references and page numbers cover all physical books as it were one. Therefore please note that you probably want to have all parts.