PDF is an open standard for electronic document sharing or distribution. There are many PDF utilities to choose from when you want to create, edit, and view PDF documents, but here’s a look at Three of the best tools for working with PDFs.

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Adobe Acrobat (Windows/Mac, Reader: Free, Pro: $299)
Acrobat Reader is Adobe’s free PDF viewing tool that’s most commonly integrated into people’s browsers. It offers commenting tools, integration with Acrobat.com online services, and a protected mode to safeguard your computer from malicious PDFs. Although it’s not as speedy as the other PDF viewers, Reader has the broadest access to all types of content embedded in PDF files. For creating, editing, and more advanced features, you’ll need to upgrade to either the Standard or Pro version or get the Suite — something probably more appropriate for businesses, given the pricing.

PDF-XChange (Windows, Reader: Free, Pro: $US34.50)
Voted the best PDF reader in a previous Hive Five, PDF-XChange is a lightweight, fast PDF reader with a long feature list, including page markup, exporting the document or pages to images, text extraction, support for 256 bit AES encryption, customizable interface, and more. The Pro version includes more page manipulation capabilities, PDF conversion and creation tools

Foxit (Windows/Linux, Reader: Free, Pro: $US129)
Foxit Reader is a free PDF reader with a small footprint but a slew of features, including PDF markup and commenting, advanced multimedia insertion, five levels of security, and even the ability to run JavaScript on the document. There are other versions of Foxit that serve different purposes: PDF Creator ($US29.99) converts other file formats to PDF, PDF Editor ($US99) lets you modify any part of the PDF file, and the Foxit Phantom PDF suite ($US129) includes all of the above capabilities plus additional ones like comparing PDF files.

BeCyPDFMetaEdit is a good solution for that. It supports edit most metadata, custom viewer preferences, slide show, page labels, etc. Tweak PDF also supports Metadata with a simple user interface but without slideshow setting and some other features.

DigiSigner is a helpful tool to digitally sign PDF files and verify signatures. With the signed documents, you can assure that the important PDF documents, such as invoices and contracts, are not tampered with.