The engine is written in Go and ships bundled in the JAR via Panama FFI (JEP 454). No JNI, no separate process. JDK 22+, one flag: --enable-native-access=ALL-UNNAMED.

  Document.create("report.pdf", doc -> {
      doc.add(Heading.of("Q3 Report", HeadingLevel.H1));
      doc.add(Paragraph.of("Revenue grew 23% year over year."));
      doc.add(Table.of(
          new String[]{"Product", "Revenue"},
          new String[]{"Widget A", "$48,000"}
      ));
  });

  HtmlConverter.toPdf("<h1>Invoice</h1><p>Due: $1,200</p>", "invoice.pdf");

https://github.com/carlos7ags/folio-java

Go engine: https://github.com/carlos7ags/folio

Playground (runs the Go engine directly): https://playground.foliopdf.dev