curl and libcurl is a tool for transferring files using URL syntax. It supports HTTP, HTTPS, FTP, FTPS, SCP, SFTP, TFTP, DICT, TELNET, LDAP, POP3, IMAP, SMTP, RTSP, RTMP, and FILE, as well as HTTP-post, HTTP-put, cookies, FTP upload, resumed transfers, passwords, port numbers, SSL certificates, Kerberos, and proxies. It is powered by libcurl, the client-side URL transfer library. There are bindings to libcurl for about 40 languages and environments.
getmail is intended as a simple, secure, and reliable replacement for fetchmail. It retrieves email (either all messages, or only unread messages) from one or more POP3, SPDS, or IMAP4 servers (with or without SSL) for one or more email accounts, and reliably delivers into qmail-style Maildirs, mboxrd files, or through external MDAs (command deliveries) specified on a per-account basis. getmail also has excellent support for domain (multidrop) mailboxes, including delivering messages to different users or destinations based on the envelope recipient address.
ZooLib allows one to write a single set of C++ sources which can be compiled into native executables for Mac OS, Windows, BeOS, or POSIX-compliant systems that use the X Window system (such as Linux). Zoolib provides a GUI toolkit with a uniquely flexible layout system. It also provides a single-file database format, TCP networking, and extensive debugging support. ZooLib applications are multithreaded. ZooLib requires only minimal support from the underlying OS and platform GUI layer, and thus could be ported to a completely new platform without too much difficulty. ZooLib is fully production quality on Windows and MacOS, completely implemented but untested on BeOS, and not yet complete on POSIX. Please note that the sources from the "demo" branch are also required to build ZooLib or to get started writing your own ZooLib applications.
MIB Smithy SDK is a dynamic extension to Tcl/Tk (8.4+) that allows development of custom scripts for controlling SNMP agents, manipulating SMI definitions, doing conversions, and more. It is based on the core of Muonics' MIB Smithy, and the SDK supports SMIv1 and SMIv2, as well as SNMPv1/v2c/v3 with HMAC-SHA-96 and HMAC-MD5-96 authentication and DES/CBC and AES128/CFB privacy. It also provides complete read-write access to all elements of SMI/MIB Module definitions, unlike similar extensions that provide only read access to a limited subset. The SDK allows multiple discrete SMI databases and SNMP sessions, and provides all of the built-in validation and error recovery capabilites of the full product, without the visual MIB development environment.
GNU SASL is an implementation of the Simple Authentication and Security Layer framework and a few common SASL mechanisms. SASL is used by network servers such as IMAP and SMTP to request authentication from clients, and in clients to authenticate against servers. The library includes support for the SASL framework (with authentication functions and application data privacy and integrity functions) and at least partial support for the CRAM-MD5, EXTERNAL, GSSAPI, ANONYMOUS, PLAIN, SECURID, DIGEST-MD5, LOGIN, NTLM, and KERBEROS_V5 mechanisms.
The sctplib library is a fairly complete prototype implementation of the Stream Control Transmission Protocol (SCTP), a message-oriented reliable transport protocol that supports multi-homing and multiple message streams multiplexed within an SCTP connection. The API of the library was modeled after section 10 of RFC 2960, and most parameters and functions should be self-explanatory to the user familiar with this document. In addition, the library also provides a number of helper functions for managing timers and UDP communication.
The PEAK library tries to achieve high performance in combining multi-threading with an efficient I/O event model. You can write event-based applications that use massive sockets I/O, timers, and signals. Its underlying I/O multiplexing engine supports kqueue(2) (FreeBSD, NetBSD, and Mac OS X), epoll(2) (Linux 2.6), and /dev/poll (Solaris). It provides support for optimized memory allocations, basic database primitives, and synchronization.
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.
yaSSL is a C++ based SSL library for embedded and RTOS environments, designed for individuals who prefer to use the C++ language. For a C-based solution, please see CyaSSL. yaSSL supports the industry standards up to TLS 1.2, and also includes an OpenSSL compatibility interface.