Subversion is a version control system. Originally designed to be a compelling replacement for CVS in the open source community, it has far exceeded that goal and seen widespread adoption in both open source and corporate environments. The Subversion project produces Subversion's core libraries (written in C), a fully functional command line client (svn), repository administration programs, API bindings for various languages (Perl, Python, Java, Ruby, etc.), and various additional tools and scripts.
MirrorBrain is a framework to run a content delivery network using mirror servers. It solves a challenge that many popular open source projects face: a flood of download requests, often magnitudes more than a single site could practically handle. A central (and probably the most obvious) part is a "download redirector" that automatically redirects requests from Web browsers or download programs to a mirror server near them. Choosing a suitable mirror for a user's request is the key, and MirrorBrain uses geolocation and global routing data to make a sensible choice and achieve load-balancing for the mirrors at the same time. The algorithm is both sophisticated and easy to control and tune. In addition, MirrorBrain monitors mirrors, scans them for files, generates mirror lists, and more.
Redland is a set of C libraries providing a high-level API for the Resource Description Framework (RDF), allowing it to be stored, parsed, serialized, queried, and manipulated. It has an object-based, modular design and comes with detailed reference documentation and examples. Redland supports all RDF vocabularies such as FOAF, RSS 1.0, Dublin Core, DOAP, and OWL, the query languages SPARQL and RDQL, and all RDF syntaxes including Turtle, RDF/XML, RDF/JSON, RSS, Atom, RDFa, and GRDDL.
Conary is a distributed software management system for Linux distributions. It replaces traditional package management solutions (such as RPM and dpkg) with one designed to enable loose collaboration across the Internet. It enables sets of distributed and loosely connected repositories to define the components which are installed on a Linux system. Rather than having a full distribution come from a single vendor, it allows administrators and developers to branch a distribution, keeping the pieces which fit their environment while grabbing components from other repositories across the Internet.
Raptor is a C library providing a set of parsers and serializers for Resource Description Framework (RDF) triples by parsing syntaxes into RDF triples and serializing triples into a syntax. The parsers support RDF/XML, N-Triples, GRDDL, and Turtle, and via RSS tag soup: XML RSS, Atom 0.3, and Atom 1.0. The serializers support RDF/XML (3 flavours), Turtle, DOT, N-Triples, RSS 1.0, and Atom 1.0. Raptor handles RDF/XML as used by RDF applications such as RSS 1.0, FOAF, DOAP, Dublin Core, and OWL. It can use either expat or libxml2 for XML parsing, libcurl when available for URI retrieval, and is portable to many POSIX systems.
mod_asn is an Apache module that uses BGP routing data to look up the autonomous system (AS) and the network prefix (subnet) which contains a given (client's) IP address. mod_asn is highly scalable. To do lookups in high-speed, it uses the PostgreSQL ip4r datatype, which is indexable with a Patricia Trie algorithm to store network prefixes. This is the most suitable algorithm, being able to search through around 250,000 existing prefixes quickly. mod_asn is usable as a standalone module, and the lookup result can be used by scripts or other Apache modules. For instance, a download redirector could base its decisions on the lookup result provided by mod_asn.
The mission of the Apache Portable Runtime (APR) project is to create and maintain software libraries that provide a predictable and consistent interface to underlying platform- specific implementations. The primary goal is to provide an API to which software developers may code and be assured of predictable if not identical behaviour regardless of the platform on which their software is built, relieving them of the need to code special-case conditions to work around or take advantage of platform-specific deficiencies or features.
Rasqal is a C library for querying RDF graphs, supporting the SPARQL, RDQL, and LAQRS languages. It provides APIs for creating a query and parsing query syntax. It features pluggable triple-stores and matching interfaces, query engines for executing the queries, an API for manipulating results as bindings, and multiple ways to format the results to XML, CSV, TSV, and JSON. It uses the Raptor RDF parser to return triples from RDF content, and can alternatively work with the Redland RDF library's persistent triple stores. It is portable across many POSIX systems.
The Apache Traffic Server (TS or ATS) is a modular, high-performance reverse proxy server, generally comparable to Squid. It was created by Inktomi, and distributed as a commercial product called the Inktomi Traffic Server, before Inktomi was acquired by Yahoo!. Traffic Server has been actively used inside of Yahoo for over 4 years, serving billions of requests every day. As of fall 2009, Traffic Server is an Open Source project, and in April 2010 the Apache Traffic Server was promoted to a top-level project of the ASF.