What are some recommended tools or libraries for working with PDF documents in PHP?

Working with PDF documents in PHP often requires the use of specialized tools or libraries to manipulate, create, or extract information from PDF files. Some recommended tools for working with PDF documents in PHP include TCPDF, FPDF, and FPDI. These libraries provide functions for creating PDF files from scratch, adding text and images, and merging existing PDF documents.

// Example using TCPDF to create a PDF document
require_once('tcpdf/tcpdf.php');

$pdf = new TCPDF();
$pdf->AddPage();
$pdf->SetFont('Arial', 'B', 16);
$pdf->Cell(0, 10, 'Hello World', 0, 1, 'C');
$pdf->Output('example.pdf', 'D');