This PECL extension is not bundled with PHP.
Information for installing this PECL extension may be found in the manual chapter titled Installation of PECL extensions. Additional information such as new releases, downloads, source files, maintainer information, and a CHANGELOG, can be located here: http://pecl.php.net/package/pecl_http.
Note: The official name of this extension is pecl_http.
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 (--with-http-zlib-compression). 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 (--with-http-magic-mime).