What are some recommended resources or libraries for keyword extraction in PHP?

Keyword extraction in PHP can be achieved using various libraries and resources. Some recommended options include using the PHP Natural Language Processing Toolkit (PHP-NLTK) for text analysis and keyword extraction, the TextRank algorithm for keyword extraction, or the TextAnalysis API for extracting keywords from text. These resources can help identify important keywords from a given text, which can be useful for tasks such as content categorization, search engine optimization, and text summarization.

// Using PHP-NLTK for keyword extraction
$text = "This is a sample text for keyword extraction using PHP-NLTK.";
$keywords = PHP_NLTK\KeywordExtractor::extract($text);
print_r($keywords);