ASIHTTPRequest is an easy to use wrapper around the CFNetwork API that makes some of the more tedious aspects of communicating with web servers easier. It is written in Objective-C and works in both Mac OS X and iPhone applications.

It is suitable performing basic HTTP requests and interacting with REST-based services (GET / POST / PUT / DELETE). The included ASIFormDataRequest subclass makes it easy to submit POST data and files using multipart/form-data.

It provides:

• A straightforward interface for submitting data to and fetching data from webservers
• Download data to memory or directly to a file on disk(i)
• The ability to submit files on local drives as part of POST data, compatible with the HTML file input mechanism
• Easy access to request and response HTTP headers
• Progress delegates (NSProgressIndicators and UIProgressViews) to show information about download AND upload progress
• Auto-magic management of upload and download progress indicators for operation queues
• Basic + Digest authentication support, credentials are automatically for the duration of a session, and can be stored for later in the Keychain.
• Cookie support
• Based on NSOperation to make queuing requests and background operation easy
• Basic unit tests (more to come!)

Documentation is available here.