pdfcrypt allows you to set permissions on a PDF file. For example, you can publish a document without permitting users to print it. The button to print the file will be disabled in the Acrobat Reader application. It can be used as a batch application to set permissions on a large group of PDF files, or as a filter in a Unix pipeline, or within a CGI application. Only binary executables are distributed, but the original Perl source code may be requested.
KDX is a powerful cross-platform BBS-style encrypted Internet communications system that provides messaging, news, file and folder transfer, voice chat (Internet Telephone), text chat, remote access, trackers, and more. It uses strong encryption to protect communications for security and privacy. It is useful for groups that need to collaborate on a project via the Internet. It is also very useful for remote administration of a computer. It uses a client/server architecture.