Apache HTTP Server
Flexible modules & per-directory rules
- Architecture
- Configurable process models. The event MPM handles keep-alive connections asynchronously; Apache is not limited to one process per connection.
- Configuration
- .htaccess supports per-directory rules when AllowOverride permits them. Module and rewrite compatibility depends on configuration.
- Caching
- mod_cache provides HTTP caching. WordPress can also use application-level caching; it requires appropriate setup and invalidation.
- License
- Open source. No commercial web-server license fee; hosting and administration still have costs.
- Good fit
- Sites that need Apache modules, familiar rewrite rules and control over server configuration.

