sfPHPView:
A view that uses PHP as the templating engine.
sfView:
A view represents the presentation layer of an action. Output can be
customized by supplying attributes, which a template can manipulate and
display.
sfViewCacheManager:
Cache class to cache the HTML results for actions and templates.
sfViewParameterHolder:
sfViewParameterHolder stores all variables that will be available to the
template.