The HttpResponse class requires at least PHP v5.1.
Any other class is available as of PHP v5.0.
Be aware though, that some methods are not available with PHP v5.0.
Installation requirements on Windows
In order to be able to load this extension on Windows,
you additionally need to load the following PHP extensions:
Installation requirements on other platforms
The extension must be built with » libcurl support
to enable request functionality (--with-http-curl-requests).
A library version equal or greater to v7.12.3 is required.
To enable support for sending and receiving compressed
responses, the extension must be built with » zlib support
A library version equal or greater than v1.2.2 is required.
Content type quessing can be enabled by
building this extension with » libmagic support