Currently the package only supports the Yahoo! Search Web Services, which is natural because Yahoo! does not expose other services via their API at the moment. Due to the modular layout of the package it is easy to add support for other services at a later point though. More information about the design of the package is available in a separate section.
The Services_Yahoo package can be installed using the PEAR installer command pear install Services_Yahoo. If the installation fails due to missing dependencies, one either needs to install them manually or can make the installer fetch all dependencies automatically: pear install -a Services_Yahoo.
Alternative installation methods for situations where one has no access to the pear installer command can be found in the general installation chapter.