MatrixSSL is an embedded SSL and TLS implementation designed for small footprint devices and applications requiring low overhead per connection. The library is less than 50K on disk with cipher suites. It includes SSL and TLS client and server support, session resumption, and implementations of RSA, AES, 3DES, ARC4, SHA1, and MD5. The source is well documented and contains portability layers for additional operating systems, cipher suites, and cryptography providers.
The stunnel program is designed to work as an SSL encryption wrapper between remote client and local (inetd-startable) or remote server. It can be used to add SSL functionality to commonly used inetd daemons like POP2, POP3, and IMAP servers without any changes in the programs' code. It will negotiate an SSL connection using the OpenSSL or SSLeay libraries. It calls the underlying crypto libraries, so stunnel supports whatever cryptographic algorithms you compiled into your crypto package.
DeleGate is a multi-purpose application level gateway or proxy server that mediates communication of various protocols, applying cache and conversion for mediated data, controlling access from clients, and routing toward servers. It translates protocols between clients and servers, converting between IPv4 and IPv6, applying SSL (TLS) to arbitrary protocols, merging several servers into a single server view with aliasing and filtering. It can be used as a simple origin server for some protocols (HTTP, FTP, and NNTP).
The OpenCA OCSP Responder is an RFC 2560 compliant OCSPD responder. It can be used to verify the status of a certificate using OCSP clients (such as Mozilla/Netscape7). The Responder is actually included in the main OpenCA distribution package. It is also possible to install the daemon as a stand-alone application, in which case you will need a CRL (or access to an LDAP server where the CRL can be obtained).
SoftHSM is an implementation of a cryptographic store accessible through a PKCS#11 interface. You can use it to explore PKCS#11 without having a Hardware Security Module. It is being developed as a part of the OpenDNSSEC project. SoftHSM uses Botan for its cryptographic operations.
jEncrypt is a commandline file encryption archiver. Files are encrypted with the AES-CTR mode, which was recommended by the National Institute of Standards and Technology in 2001 (NIST SP 800-38A). AES-CTR mode only provides confidentiality. It requires a message authentication code such as CBC-MAC to ensure an encrypted message is not accidentally modified or maliciously tampered with, which jEncrypt currently does not provide.