A list of the 6 libraries in the architecture teensy.

GUIslice GUIslice embedded touchscreen GUI library in C for Arduino & Raspberry Pi
Hello Drum Arduino Library for piezo sensing
Mcp3208 Arduino library for the MCP320x 12 bit ADC family.
MFRC522 Arduino RFID Library for MFRC522 (SPI)
PJON PJON is an open-source, multi-master, multi-media bus network protocol
Watchdog Use Watchdog to execute a function and/or reset the microcontroller.