According to their website, CutePDF Writer (formerly CutePDF Printer) is the free version of commercial PDF creation software. CutePDF Writer installs itself as a "printer subsystem". This enables virtually any Windows applications (must be able to print) to create professional quality PDF documents. It's free because they want you to also buy CutePDF 3.0 (formerly CutePDF Plus) for $49.95 with CutePDF Writer and CutePDF Form SDK. CutePDF Form Filler can be used to save PDF forms to your computer to fill in at your convenience, e-mail completed forms, and apply 128-bit encryption or password protection before submitting. CutePDF Form SDK enables your applications to process interactive PDF forms, FDF/XFDF/XML data files on the fly.