Focused crawls are collections of frequently-updated webcrawl data from narrow (as opposed to broad or wide) web crawls, often focused on a single domain or subdomain.
Makes the algorithms and APIs defined by URL Standard (replaces RFC 3986 and RFC 3987) available on PHP. / URL Standard (RFC 3986、RFC 3987 を置き換える Web 標準仕様) で定義されているアルゴリズム、および API を PHP から利用できるようにします。