This library provides a C99 implementation of the HTTP/1.1 and HTTP/2 specifications.

Portable C toolchain with a focus on simplicity. Includes, among other things, a compiler, a make implementation, and an implementation of several utilities normally provided by binutils (e.g., nm(1) or addr2line(1)). Further, it also comes with its own C standard library implementation.

Concurrency Kit (ck) provides concurrency primitives, safe memory reclamation mechanisms and non-blocking (including lock-free) data structures designed to aid in the research, design and implementation of high performance concurrent systems developed in C99+.

This C library contains some essential string manipulation functions and more, like escaping special characters.

minIni is a portable and configurable library for reading and writing .ini files.

Calcurse is a text-based calendar and scheduling application. It helps keep track of events, appointments and everyday tasks. A configurable notification system reminds user of upcoming deadlines, and the curses based interface can be customized to suit user needs. All of the commands are documented within an online help system.

gsimplecal is a lightweight calendar application written in C++ using GTK. Launched once, it pops up a small calendar applet, launched again it closes the running instance. It can additionally be configured to show the current time in different timezones.

Gcal is a program to calculate and print calendars on the command-line. Calendars can be printed in 1-month, 3-month or whole-year views. In addition, eternal holiday lists can be generated for many countries, which can be complemented by user-made lists of fixed dates to make an agenda. Gcal can also calculate astronomical data, such as the phases of the moon, and supports alternative calendar formats: Julian, Gregorian, Islamic, Chinese and more.

Khal is a standards based console calendar program, able to synchronize with CalDAV servers through vdirsyncer. It includes both a CLI and a TUI named 'ikhal'.

By default, date2name gets the modification time of matching files and directories and adds a datestamp in standard ISO 8601+ format YYYY-MM-DD at the beginning of the file or directory name.

adl-submit is a tool that can be used to submit events to any instance of the Agenda Du Libre (a web calendar originally meant for free software events). Users can set fields through the command line or create an XML that can be submitted with the adl-submit tool. While the Agenda Du Libre web application is available in multiple languages, most of the events on https://www.agendadulibre.org are in French and the adl-submit tool is only available in French.

Remind allows you to remind yourself of upcoming events and appointments. Each reminder or alarm can consist of a message sent to standard output, or a program to be executed. It also features: sophisticated date calculation, moon phases, sunrise/sunset, Hebrew calendar, alarms, PostScript output and proper handling of holidays.

Libical is an implementation of the iCalendar protocols and protocol data units.

ConfClerk is an application written in Qt, which makes conference schedules available offline. It displays the conference schedule from various views, support searches on various items (speaker, speech topic, location, etc.) and enables you to select favorite events and create your own schedule.

At the moment ConfClerk is able to import schedules in XML format created by the PentaBarf conference management system (or frab) used by e.g. FOSDEM, DebConf, FrOSCon, Grazer LinuxTage, and the CCC congresses.

ConfClerk is targeted at mobile devices but works on any system running Qt.

ddate displays the Discordian date and holidays of a given date. The Discordian calendar was made popular by the "Illuminatus!" trilogy by Robert Shea and Robert Anton Wilson.

Hebcal is a program for converting between Hebrew and Gregorian dates, and generating lists of Jewish holidays for a given year. Shabbat, holiday candle lighting, and havdalah times are approximated using your location.

It can also show daily prayer times, the weekly Torah reading, and the daily leaf of Talmud. The program can help with counting of the Omer or with calculation of Hebrew yahrzeits, birthdays, or anniversaries.

Date is a header only C++ library that extends the chrono date algorithms library for calendar dates and durations. It also provides the <tz.h> library for handling time zones and leap seconds.

LibHdate is a small library for the Hebrew calendar and times of day, written in C, and including bindings for C++, pascal, perl, php, python, and ruby. It includes two illustrative command-line programs, hcal and hdate, and some snippets and scripts written in the binding languages.

ccal is a command line program which writes a Gregorian calendar together with Chinese calendar to standard output. Its usage is similar to the cal program. In addition to console output, it can also generate Encapsulated Postscript and HTML table outputs for use in do-it-yourself calendars and web pages. It supports both simplified and traditional Chinese characters.

Ccache is a compiler cache. It speeds up recompilation by caching previous compilations and detecting when the same compilation is being done again. Supported languages are C, C++, Objective-C and Objective-C++.

cdrecord converts a CD image in a ".bin / .cue" format (sometimes ".raw / .cue") to a set of .iso and .cdr tracks.

cdrdao records audio or data CDs in disk-at-once (DAO) mode, based on a textual description of the contents. This mode writes the complete disc – lead-in, one or more tracks, and lead-out – in a single step and is commonly used with audio CDs. cdrdao can also handle the bin/cue format, commonly used for VCDs or disks with subchannel data.

abcde is a front-end command-line utility (actually, a shell script) that grabs tracks off a CD, encodes them to Ogg/Vorbis, MP3, FLAC, Ogg/Speex and/or MPP/MP+ (Musepack) format, and tags them, all in one go.

geteltorito can extract the initial/default boot image from CDs (and ISOs) that follow the El Torito specification for bootable CD-ROMs.

Image data is written to standard output by default and all other information is written to standard error.