pyratemp is probably (one of) the smallest complete template-engines for Python (with about 500 LOC). It has a very small set of special syntax in the templates. This reduces complexity and the probability of bugs and lead to an easy-to-use and intuitive user-interface. It uses embedded Python-expressions (in a "sandbox"), is well documented, has full Unicode-support, and produces very good error-messages, which is very useful when creating new templates.
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.
Karaoke con SMIL is a project to synchronize audio, text, and images and export the final result to SMIL, which can be played in multimedia players such as Real Player, Helix Player, Ambulant Player, etc. on several devices (computers, mobile phones, PDAs, etc.). In short, this application synchronizes the multimedia elements in a way similar to karaoke.
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.
itools is a collection of Python libraries which provides a wide range of capabilities, including an abstraction over directory and file resources, a search engine, type marshallers, datatype schemas, i18n support, URI handlers, a Web programming interface, a workflow interface, and support for data formats such as (X)HTML, XML, iCalendar, RSS 2.0, and XLIFF.
boodebr is a collection of Python modules from boodebr.org. boodebr.ion provides JSON and XML serialization with a common API (internal and external). boodebr.config provides flexible configuration file handling (similar to INI files, but using JSON/XML with full object pickling).
WikklyText is a Python-based wiki and modular library for creating custom wikitext rendering applications. Its wikitext engine is compatible with the TiddlyWiki markup language. It functions equally well as a wiki-on-a-stick or as a multiuser wiki behind Apache. It includes a Drupal plugin as well.
PyYAML is a YAML parser and emitter for Python. PyYAML features a complete YAML 1.1 parser, Unicode support, pickle support, capable extension API, and sensible error messages. PyYAML supports standard YAML tags and provides Python-specific tags that allow the representation of an arbitrary Python object. PyYAML is applicable for a broad range of tasks from complex configuration files to object serialization and persistence.
xhtml2pdf converts HTML/XHTML/XHML to PDF using the ReportLab Toolkit, the HTML5lib, and pyPdf. It supports HTML 5 and CSS 2.1 (and some of CSS 3). The main benefit of this tool that a user with Web skills like HTML and CSS is able to generate PDF templates very quickly without learning new technologies.