Libxml2 is the XML C library developed for the Gnome project. The library code is portable (to Linux, Unix, Windows, embedded systems, etc.) and modular; most of the extensions can be compiled out. Libxml2 implements a number of existing standards related to markup languages, including the XML standard, Namespaces in XML, XML Base, Relax NG, RFC 2396, XPath, XPointer, HTML4, XInclude, SGML Catalogs, and XML Catalogs. In most cases, libxml tries to implement the specifications in a relatively strict way. To some extent, it provides support for the following specifications, but doesn't claim to implement them: DOM, FTP client, HTTP client, and SAX2. Support for W3C XML Schemas is in progress. It includes xmllint, a command line XML validator.
eXist is a native XML database featuring efficient, index-based XQuery processing. It provides a complete ecosystem for building applications entirely based on XML, XQuery, and related standards. The high-performance XML database engine stores textual or binary data and documents without requiring a database schema. Using XML across all layers makes mapping technologies superfluous and increases productivity. A browser-based IDE and a standardized application packaging system help developers get started quickly.
Mini-XML is a small XML parsing library that you can use to read XML and XML-like data files in your application without requiring large non-standard libraries. It only requires an ANSI C compatible compiler (GCC works, as do most vendors' ANSI C compilers) and a "make" program. It supports reading of UTF-8 and UTF-16 and writing of UTF-8 encoded XML strings and files, and provides a hierarchical view of the file via a linked-list tree structure of typed nodes and functions for managing, traversing, indexing, and searching the tree.
Libxslt is a C library for GNOME which allows developers to work with XSLT. It is based on libxml for XML parsing, tree manipulation, and XPath support. Also included is 'xsltproc', a command line XSLT processor. The library is written in plain C, making as few assumptions as possible, and sticking closely to ANSI C/POSIX for easy embedding. It should work on Linux, Unix, and Windows. Though not designed primarily with performances in mind, libxslt seems to be a relatively fast processor. It also include full support for the EXSLT set of extension functions as well as some common extensions present in other XSLT engines.
metaf2xml can download, parse, and decode aviation routine weather reports (METAR, SPECI, SAO), aerodrome forecasts (TAF), synoptic observations (SYNOP), and BUOY observations, and store the data as XML. XSLT style sheets convert it to plain language, as HTML or text. Current weather data from NOAA and other sources can be fetched and displayed.
Sketsa SVG Editor is a vector drawing application based on SVG. It allows users to create vector graphics that can be scaled and printed at any resolution, without losing detail or clarity. It features various tools for optimizing content creation, and includes a property palette, a DOM editor, a source editor, a resource editor, SVG-specific shape tools, transformation tools, and additional illustration tools. It uses SVG as its native file format.
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.