Entirely built on Grand Central Dispatch for best performance and no-hassle multithreading
Well designed API for easy integration and customization
Minimal number of source files and no dependencies on third-party source code
Support for streaming large HTTP bodies for requests and responses to minimize memory usage
Built-in parser for web forms submitted using "application/x-www-form-urlencoded" or "multipart/form-data"
Available under a friendly New BSD License

What's not supported (yet?):

Keep-alive connections
Authentication
HTTPS
Web forms submitted using "multipart/mixed"

Requirements:

OS X 10.7 or later
iOS 5.0 or later

Example 1: Hello World

A simple HTTP server that runs on port 8080 and returns a "Hello World" HTML page to any request:

// Create server and add default handler
GCDWebServer* webServer = [[GCDWebServer alloc] init];
[webServer addDefaultHandlerForMethod:@"GET"
                         requestClass:[GCDWebServerRequest class]
                         processBlock:^GCDWebServerResponse *(GCDWebServerRequest* request) {
  
  return [GCDWebServerDataResponse responseWithHTML:@"<html><body><p>Hello World</p></body></html>"];
  
}];

// Run server on port 8080 until SIGINT received
[webServer runWithPort:8080];

// Destroy server
[webServer release];

Languages

Objective-C 83.3%

JavaScript 10.5%

Swift 2.1%

HTML 1.9%

Shell 1%

Other 1.2%