For current information about PGP, and for the most recent versions, see the International PGP Home Page: http://www.pgpi.com/ This site also has documentation, Frequently Asked Questions (FAQ) documents, news, and lots more. My own recommendation as to what version of PGP you should run: - get a version for which source is available; while NAI owned PGP, this meant avoiding the most recent binary-only versions. For current versions of Windows PGP, this is no longer a concern, since source is available. - get a version which supports RSA keys; some people still use RSA keys--to communicate with these people, you will not only need to be able to use RSA keys, but may also need to be able to generate an RSA key of your own. See RJ Marquette's PGP Interactions page, http://www.rmarq.pair.com/pgp/ for information. Windows 95/98/NT/2000 users: PGP 8.0 is the most recent version of Windows PGP. It was released, with source, in December 2002 by PGP Corporation, which purchased the PGP code from Network Associates in August 2002 after NAI abandoned PGP. This version fully supports Windows XP. Mail client support for the freeware version may not be as good as that in older versions of Windows PGP. A somewhat older version is PGP-7.0.3, from NAI; it is somewhat more up to date than 6.5.8, and contains more encryption algorithms. Source was not available for this version, but Phil Zimmerman vouched for its integrity. Be sure to install the Hotfix as well. See Phil Zimmerman's statement on leaving NAI for more details: http://www.pgpi.org/files/PRZquitsNAI.txt PGP6.5.8 was for some time the most recent version for which source was available, or use 6.5.1int if you want the "international" version. A Windows command line version of GnuPG is also available. WinPT, a Windows frontend for GnuPG is also available, and may be an acceptable alternative to PGP. Unix/Linux/*BSD: A Unix version of PGP6.5.8 is available, but I haven't tested it. GnuPG (GNU Privacy Guard) is available from the GNU project; it is fully interoperable with PGP, and is the recommended version for Unix/Linux/*BSD users. See http://www.gnupg.org/. Unix users may also wish to keep a copy of pgp2.6.3ia around if they need to communicate with people who only have access to PGP 2. Information files (these are pretty old): getpgp Where to get the latest versions of PGP pgp-faq Answers to PGP Frequently Asked Questions (FAQ) pgpbg11.asc PGP Beginner's Guide Various versions of PGP are available in subdirectories: pgp263i Most recent "classic" PGP version (2.6.3ia -- patchlevel 'a'). Use this if you want PGP version 2. See pgp263i/readme.1st for details. pgp8 PGP version 8; Windows only. pgp7 PGP version 7; Win9x only. pgp6 PGP version 6; Win95/98/NT and Unix gnupg GnuPG (Gnu Privacy Guard) The following versions are probably of historical interest only: pgp5 PGP version 5; Win95/98/NT and Unix pgp262i Predecessor to 2.6.3i pgp262 Last MIT PGP version, 2.6.2. pgp26i Predecessor to 2.6.2i pgp261 Old MIT version. pgp26 Old MIT version. pgp25 Old MIT version. pgp23A Standard PGP version before MIT versions appeared. pgp26ui Version 2.3A, modified to deal with MIT versions. macpgp Some older Macintosh versions. See www.pgpi.com for more recent Mac versions. WWW: The best place to get started with PGP is the International PGP Home page, at .