Zoidberg (a.k.a. zoid) provides a modular Perl shell written, configured, and operated entirely in Perl. It aspires to be a fully operational login shell with all the features one normally expects. But it also gives direct access to Perl objects and data structures from the command line, and allows you to run Perl code within the scope of your command line.
Xapian is a search engine library, scalable to collections containing hundreds of millions of documents. It's written in C++ with bindings for Perl, Python, PHP, Java, Tcl, C#, Ruby, and Lua. It is a highly adaptable toolkit that allows developers to easily add advanced indexing and search facilities to their own applications. It supports the Probabilistic Information Retrieval model and also a rich set of boolean query operators. Omega is a Web search application built upon the Xapian library. It can index a Web server's document tree (including HTML, PDF, OpenOffice, MS Word/Excel/Powerpoint/Works, WordPerfect, RTF, PS, etc.), or data exported from arbitrary sources (e.g. SQL databases).
Berkeley DB XML is a native XML database engine for use within your product. Made available as a C++ library with language bindings for Java, Perl, Python, PHP, and Tcl, it integrates directly into your application (it is not a standalone database server). It provides XQuery access into a database of document containers. XML documents are stored and indexed in their native format using Berkeley DB as the transactional database engine.
The TunePimp library is an audio file tagging library that uses MusicBrainz for track identification/lookup. It will attempt to automatically identify the files, and will present the user with possible matches for files that are not automatically identified. Once the files are identified, it writes new metadata tags to the music files and writes the files to a user-defined directory hierarchy. It supports WAV, MP3, Ogg Vorbis, and FLAC files.
ACFTools is a utility for manipulating X-Plane flight simulator aircraft and weapon models without using its Plane Maker. It can decode both Apple and Intel ACF/WPN formats into plain text files with a syntax similar to C, which can be edited and then re-converted into binary data. It is able to extract almost complete 3D models of aircraft (fuselage, floats, tanks, wings, stabs, propellers, engines) and write it in AC3D modeler format. Edited 3D parts can then be merged into plain text and consequently converted into binary ACF files.
Gtk2::Ex::DBI is a Perl module that is used in conjunction with Gtk2::Perl and Gtk2::GladeXML to give data-aware "form" functionality. The programmer creates a database form with Glade2, and then creates a Gtk2::Ex::DBI object, which then "binds" a DBI data source to the form, managing querying, navigating records, applying updates to the database, and error handling.