After install Foxit Reader 6, I noticed it has integrate with DocuSign to offer Bring eSignature to Foxit Reader users, after some search I got the following information,

SAN FRANCISCO – September 6, 2012 - DocuSign, the global standard in eSignature^®, and Foxit^®, a leading software provider of solutions for reading, editing, creating, organizing and securing PDF documents, today announced the integration of Foxit as part of the DocuSign eSignature solution. In addition, Foxit will distribute DocuSign’s service worldwide as an integrated capability of Foxit Reader and PhantomPDF. This easy-to-use integration helps Foxit users quickly and securely sign and send documents using the world’s most widely used eSignature solution – while creating an even better experience for DocuSign users.
“Our agreement with Foxit further solidifies DocuSign as the global standard for eSignature and gives users around the world a more powerful way to sign documents,” said Keith Krach, chairman and CEO of DocuSign. “We also made the decision to replace Adobe Reader with Foxit Reader in DocuSign’s eSignature Transaction Management platform to benefit our more than 20 million customers who use DocuSign every day to sign more than 150,000 documents.”
“We are thrilled DocuSign has made Foxit part of its industry-leading eSignature platform,” said Eugene Xiong, CEO of Foxit Corporation. “Foxit’s 130 million plus customers worldwide can now DocuSign directly from Foxit Reader and PhantomPDF with the click of a button, bringing tremendous value and convenience to Foxit users everywhere.”
Foxit users can now easily sign and send documents for signature directly from Foxit with DocuSign by instantly creating a new DocuSign account or signing into their existing DocuSign account. Signing is always free, and the first five documents a user sends for signature are complimentary, after which subscription plans start as low as $15 per month for individual professionals with plans available for businesses of every size.
DocuSign is integrating with Foxit to create an even better user experience:

• Foxit has received many strong reviews from users and leading publications like PC World and PC Magazine
• Reviews note that Foxit takes far less memory, is faster and less intrusive than other products
• Users have noted Foxit’s interface and document markup tools as competitive differentiators

“DocuSign selected Foxit as our default PDF viewer for our customers because it takes less memory, is faster, and is less intrusive than other solutions,” said Tom Gonser, chief strategy officer at DocuSign. “Foxit has a number of unique document tools that make it a richer experience for DocuSign customers. Now Foxit PDF users can send any PDF they are viewing for signature using the secure DocuSign network right from Foxit. Of course, DocuSign users will continue to be able to sign any type of document, including those who need to sign Adobe PDF formatted documents.”
Global enterprises, business departments, individual professionals and consumers are standardizing on DocuSign, with 60,000 new users joining the DocuSign Global Network every day. Today, that network includes 20 million users who have DocuSigned more than 180 million documents in 188 countries – including employees at 90 percent of the Fortune 500.
Foxit users interested in doing business faster and better with DocuSign’s eSignature solution can get more information at http://www.docusign.com.
Customers choose Foxit products since they are fast, affordable, secure, and easy to deploy. With more than 130 million users, award winning Foxit PDF solutions have been chosen by more than 90,000 customers in more than 150 countries. Since Foxit products are ISO 32000-1 / PDF 1.7 standard compliant, they are compatible with other PDF products like those from Adobe^®.

From, DocuSign and Foxit Bring eSignature to 130 Million Customers

Foxit Reader 6, unlike other free PDF readers, with many exciting new features and feature enhancements,

New Features:

1.       PDF Creation

Allows users to quickly and easily create PDF.

1)       With one-click, create from Microsoft  Word, PowerPoint, and Excel through the Foxit Reader plug-in.

2)       High performance PDF conversion from hundreds of file types by:

a)       Dragging and dropping the document into Foxit Reader.

b)       Using the Foxit Reader create From File capability.

c)       Right mouse clicking on the file.

3)       Convert hardcopy documents into PDF with the create From Scanner functionality.

4)       Extend any application with print capabilities to include PDF conversion through the included Foxit Reader PDF Printer (PDF print driver).

5)       Cut and paste content via the Windows clipboard into a new PDF by using the From Clipboard feature.

2.         Ribbon-Based Toolbar

New user interface with a ribbon-based toolbar based on Microsoft Office 2013 (Office 15) design is more intuitive and provides users with a familiar user experience.

3.         Read and Search PDF Portfolios

Open and read PDF portfolios and perform searches either within a single PDF file or across all the PDF files in the portfolio.

4.         Whitelist Trusted URLs for Form Submission

Enables users to create and maintain a whitelist of the trusted URLs when submitting form online to manage the file access.

5.         Create and Insert Stamps

Allows users to create and insert stamps into their PDF documents and forms, by selecting from a choice of pre-made stamps, creating static custom or dynamic stamps.

6.         PDF Sign

Allows users to sign documents with their own handwriting. Signatures can be created from an image of your signature or by writing it yourself on touch enabled desktop systems or tablets. Users can quickly and easily manage, place, and apply these signatures.

7.         Plug-in Manager

Adds plug-in Manager which shows a list of installed plug-ins and the relevant information.

Feature Enhancements:

1.       Comments Summary

Supports sorting comments by checkmark status, setting current properties of any comment as default, and deleting comment by batch. Plus, the Note comment now supports to be printed.

2.       Booklet Printing

Allows users to print multipage PDF in booklet format.

3.       Run Script Right Control

Supports to control the right of running Script for better PDF protection.

reference,

http://www.foxitsoftware.com/Secure_PDF_Reader/

PDFTextStream is a  PDF content extraction library for Java and .NET(in fact, the .NET version is compiled with IKVM).
PDFTextStream is similiar to PDFBox(Open source), but it is a commercial product, could not be used free before v2.6.
Compare to PDFBox, another difference is  PDFTextStream is much faster than PDFBox( I got the report from the home page of PDFTextStream without testing).

Because of the realities of the economics around developing and maintaining a product like PDFTextStream, its pricing has often been out of reach of many projects and very small organizations that really need high-quality PDF content extraction functionality. That’s not to say that PDFTextStream is overpriced — it’s actually less expensive than other options — but that is small comfort to many that simply cannot afford or cannot justify the expenditure yet.
This change should fix that: if you have a smaller project, are working on a startup, are involved in information research, etc., you can now benefit from all that PDFTextStream has to offer.

for more details, please visit here.