The GNU Modula-2 compiler is one of a number of front end languages to GCC (the GNU Compiler Collection). As such, it has been designed to coexist with other GCC languages. For example, it can be used in mixed language projects and it can catch C++ exceptions and throw exceptions which can be caught by C++. Users can also exploit conditional compilation and full gcc backend optimization and architecture coverage. GNU Modula-2 can produce position independent code and can easily produce shared libraries from modules. The compiler provides a swig interface file generator option, which allows scripting languages such as Python to import modules written in Modula-2 and also catch exceptions thrown by Modula-2. The compiler translates PIM2, PIM3, PIM4, and ISO dialects of Modula-2.
GNU Recutils is a set of tools and libraries to access human-editable text-based databases called recfiles. A recfile contains data structured as a sequence of records. The rec format supports data integrity with the usage of record descriptors (keys, mandatory fields, field types, etc.) as well as the ability of record fields to refer to other records. Despite its simplicity, recfiles can be used to store medium-sized databases. The GNU recutils suite comprises a texinfo manual describing the Rec format, a C library (librec) providing a rich set of functions to access rec files, a set of C utilities that can be used in shell scripts and in the command line to operate on rec files, and an Emacs mode (rec-mode).
The HOTP Toolkit package contains tools that are useful when deploying the one-time password HOTP technology. It contains a shared library, a command-line tool to generate and validate one-time passwords, and a PAM module (pam_hotp) to make system login or SSH use HOTP one-time passwords for authentication.
Loomes' Nested Set is a class that can be used to manage a tree of information stored in a database. It can perform several types of operations to manipulate a hierarchy of nodes that are stored in a database as table records. Currently, it can insert a root node, insert a node that is child of a given parent, delete a branch of nodes under a given node, delete a single node, rename a node, move nodes, check whether the root node exists, and retrieve the whole tree of nodes.
GNU Mailutils is a rich and powerful protocol-independent mail framework. It contains a series of useful mail libraries, clients, and servers. These are the primary mail utilities for the GNU system. The central library is capable of handling electronic mail in various mailbox formats and protocols, both local and remote. Specifically, this project contains a POP3 server, an IMAP4 server, and a Sieve mail filter. It also provides a POSIX "mailx" client and a collection of other handy tools.
GNU Anubis is an SMTP message submission daemon. It represents an intermediate layer between the mail user agent (MUA) and mail transport agent (MTA), receiving messages from the MUA, applying to them a set of predefined changes, and finally inserting modified messages into an MTA routing network. The set of changes applied to a message is configurable on a system-wide and per-user basis. The built-in configuration language used for defining sets of changes allows for considerable flexibility and is easily extensible.
GNU Radius is a RADIUS server and an accompanying set of monitoring utilities. It features MySQL and PostgreSQL interfaces for authentication and/or logging (the ODBC interface allows you to use almost any existing DBMS for that purpose), the ability to rewrite RADIUS requests from various NASs to normalize them to a more understandable format, and the ability to completely customize the behavior of RADIUS authentication and accounting based on NAS and user attributes.
GNU `tar' saves many files together into a single tape or disk archive, and can restore individual files from the archive. It includes multivolume support, the ability to archive sparse files, automatic archive compression/decompression, remote archives and special features that allow `tar' to be used for incremental and full backups. It also includes `rmt', the remote tape server (the `mt' tape drive control program is in GNU `cpio').