citrus is a simplified 3DS homebrew library, originally known as ctrcommon. It is split into various distinct "modules":

• core - Main module, initializes everything else and contains the most basic functions.
• app - Application management functions.
• battery - Battery status functions.
• err - Error management functions.
• fs - Filesystem functions that aren't covered by the standard library.
• gpu - OpenGL-esque GPU functions.
• gput - GPU Tools; provides a default shader, a matrix stack, and higher-level drawing functions.
• hid - Input functions.
• ir - Infrared communication functions.
• news - Notification management functions.
• nor - NVRAM access functions.
• snd - Sound playback functions.
• soc - Internal module for initializing and cleaning up sockets.
• utf - UTF conversion functions.
• wifi - WiFi status functions.

Core functions:

• ctr::core::init() - Must be called before using any citrus functions.
• ctr::core::cleanup() - Must be called after you're finished using citrus functions, usually on exit.
• ctr::core::running() - Performs the standard APT main loop and returns whether or not the application should terminate.
• ctr::core::launcher() - Returns whether the application was launched from the homebrew launcher.
• ctr::core::time() - Returns the current time in milliseconds.

citrus also comes with a small set of tools, including bannertool, makerom, template RSFs, and a template Makefile.

An example of citrus and its tools in use can be found here.

Requires devkitARM, the great-refactor branch of ctrulib, and picasso to build. Run 'make' to build, and run 'make install' to install it to your devkitPro directory.

• Standard UI module, to make the creation of UIs easy.