Berkeley DB (libdb) is a programmatic toolkit that provides embedded database support for both traditional and client/server applications. It includes b+tree, queue, extended linear hashing, fixed, and variable-length record access methods, transactions, locking, logging, shared memory caching, database recovery, and replication for highly available systems. DB supports C, C++, C#, Java, PHP, and Perl APIs. It supports key-value pair (NoSQL), SQL, and Java Object formatted data. It is available for a wide variety of Unix platforms as well as QNX, Android, Mac OS X, and several varieties of Windows.
Linphone is an audio and video Internet phone with GTK+ and console interfaces. It uses the SIP protocol, and is compatible with most SIP clients and gateways. It can use various audio and video codecs such as Speex, GSM, G711, G722, ilbc, amr, Theora, H263-1998, MPEG4, H264, VP8, and snow.
Yate is a next-generation telephony engine. While currently focused on Voice over Internet Protocol (VoIP) and PSTN, its power lies in its ability to be easily extended. It supports SIP, H.323, IAX, MGCP, Jingle, Jabber, E1, T1, analogic, robbed bit, ISDN PRI, BRI, and SS7. YateClient is an Instant Messenger and Voice application for Jabber/Jingle IM, SIP, H.323, and IAX VoIP protocols.
TacitPixel (formerly libTAP ) is a prototyping system for virtual reality and augmented reality applications. It runs on a variety of platforms. RAP (rapid application prototyping) is done through the Lua interface, which mirrors the C++ namespace as closely as possible. libTAP has a small but distinctive feature set, focused on prototyping of realtime 3D simulations.
strongSwan is a complete IPsec implementation for the Linux, Android, Maemo, FreeBSD, and Mac OS X operating systems. It interoperates with with most other IPsec-based VPN products via the IKEv2 or IKEv1 key exchange protocols. The focus of the strongSwan project is on strong authentication mechanisms using X.509 public key certificates and optional secure storage of private keys on smartcards through a standardized PKCS#11 interface. A rich choice of modular plugins adds additional features like Trusted Network Connect or advanced cryptographical algorithms.
Universal Password Manager (UPM) allows you to store usernames, passwords, URLs, etc. in an encrypted database protected by one master password. Its three strongest features are simplicity (it provides a small number of very strong features with no clutter), the ability to run cross-platform, and database sharing. Rather than having many separate databases (home, work, etc.), database sharing allows you store your database at a remote location (password protected HTTP URL, for example) and then have UPM automatically keep your local database in sync with the remote database.
Mediastreamer is a portable C library that allows you to create and run audio and video streams. It is designed for any kind of voice over IP applications. It features RTP connectivity, audio codecs (Speex, iLBC, G711, GSM, and AMR), video codecs (MPEG4, H263, H264, and Theora), sound card I/O, wav file streaming, webcam video capture, echo-cancellation, conferencing, parametric equalization, and various other utilities. It has a modular design that makes it extensible through plugins. This is the media-streaming component of linphone, a GPL SIP video phone.