PGP Pipe allows encrypting a data stream of arbitrary length with the IDEA chipher from PGP. It is fast and usefull for secure backups on tapes or across the network. To prevent that this program is considered "strong cryptography", the encryption routines are NOT included, so you have to get the PGP source to compile it.
pks-commands.php3 allows your Web server to search and add PGP/GPG keys from the public keys out there. It takes the TCP 11371 port connection and does it all on the web server. It is good in environments where the client machines are unable to get to arbitrary TCP ports (such as behind tightened firewalls).
PLIB is a set of libraries to write games and other realtime interactive applications that are 100% portable across a wide range of hardware and operating systems. It's used by Majik3D, FlightGear, and others, and includes libraries for GUI widgets, sound replay, geometry, scene graph, joystick, and fonts/text.
PPTP Client allows you to connect to a PPTP server from a Linux box. It sets up a PPTP call, after which the PPP daemon establishes a PPP link over that PPTP call. The client can access PPTP-based VPNs. Besides remote access to internal corporate networks, some CATV and ADSL ISPs are using PPTP to provide Internet access to their customers.
PureTLS implements the SSLv3 and TLSv1 protocols, with a number of cipher suites. Both client authentication and renegotiation are supported. PureTLS is able to read keys out of a subset of OpenSSL-style keyfiles, which makes generating keying material easy (i.e., use OpenSSL). No support for key generation is currently provided, but it may be provided in a future release.
pyCA is a project to create Certification Authority in Python. It will generate a CA certificate hierarchy and initial CRLs, generate certificate requests with widely used web browsers, provides a search tool for client certificates in the OpenSSL certificate database, download of client certificates/certificate revocation lists with appropriate MIME types, storing all certificate data in LDAP repositories, scripts for the handling of the certification process on a non-networked system holding the CA's private key(s) and fairly easy configuration based on the OpenSSL configuration file.