acroform
Pure-Rust PDF SDK — rendering, extraction, forms, PDF/A, signatures, redaction. Bindings for Rust, Python, Node.js, .NET, Java, C, WebAssembly. AGPL-3.0 or a commercial licence.
Turn flat PDFs into real, fillable AcroForms - permissive (Apache-2.0), deterministic, zero-copyleft.
Python client for the PDFops API — fill AcroForm PDFs, merge PDFs, inspect form fields, generate invoices. One HTTP call, no native deps.