GNU libmicrohttpd is a small C library for embedding HTTP server functionality into other applications. It is reentrant, fast, supports HTTP 1.1, and permits listening on multiple ports. The API is simple and still powerful enough to allow programmers to use the entire HTTP feature set. SSL/TLS support is available as an option.
GCompris is an educational software suite with numerous activities for children aged 2 to 10. Some of the activities are game-orientated, but nonetheless still educational. These include computer discovery (keyboard, mouse, different mouse gestures), algebra (table memory, enumeration, double entry table, mirror image), science (the canal lock, the water cycle, the submarine, electric simulation), geography (place the country on the map), games (chess, memory, connect 4, oware, sudoku), reading practice, and others (learn to tell time, puzzles of famous paintings, vector drawing, cartoon making, etc.). It currently offers in excess of 100 activities, and more are being developed.
aria2 is a utility for downloading files. The supported protocols are HTTP(S), FTP, BitTorrent, and Metalink. It has a powerful segmented downloading ability, downloading a file from multiple sources and multiple protocols and utilizing your download bandwidth to the maximum. It supports downloading a file from HTTP(S)/FTP and BitTorrent at the same time, while the data downloaded from HTTP(S)/FTP is uploaded to the BitTorrent swarm. Using Metalink's chunk checksums, aria2 automatically validates chunks of data while downloading a file like BitTorrent.
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.
Splunk is an engine for machine data. Use Splunk to collect, index, and harness the fast moving machine data generated by all your applications, servers, and devices: physical, virtual, and in the cloud. Search and analyze all your real-time and historical data from one place. Splunking your machine data lets you troubleshoot problems and investigate security incidents in minutes, not hours or days. Monitor your end-to-end infrastructure to avoid service degradation or outages. Meet compliance mandates at lower cost. Correlate and analyze complex events spanning multiple systems. Gain new levels of operational visibility and intelligence for IT and the business.
The GNU Gatekeeper is a free H.323 gatekeeper based on the OpenH323 project. You can use it to manage a Voice-over-IP network and let endpoints (e.g., Netmeeting) communicate through symbolic names. It also has an external interface for billing and other applications. It runs on a number of Unix versions (including Linux and Solaris) and Windows.
Suricata is an Intrusion Detection and Prevention (IDS/IPS) engine developed by the Open Information Security Foundation and its supporting vendors. The engine is multi-threaded and has native IPv6 support, file extraction capabilities, and many more features. It's capable of loading existing Snort rules and signatures, and supports many frontends through Barnyard2.
FBReader is an e-book reader. It currently works on the Sharp Zaurus, Siemens Simpad with Opensimpad ROM, Nokia Internet Tablet (Maemo platform), Archos PMA430, Motorola E680i/A780/A1200 smartphones, PepperPad 3, Asus Eee PC, IRex iLiad, UMPC, and desktop computers running Linux, Windows XP/Vista, or FreeBSD. It supports several e-book formats: epub, plucker, palmdoc, zTXT, HTML, CHM, fb2, TCR (psion text), OEB, OpenReader, RTF, non-DRM'ed Mobipocket, and plain text.