A list of the 19 libraries in the architecture teensy.

Adafruit SleepyDog Library Arduino library to use the watchdog timer for system reset and low power sleep.
Blynk_Teensy Enable Blynk support of Teensy boards, especially latest Teensy 4.0/4.1, using WiFi, Ethernet, BT/BLE and GMSM/GPRS shields
Easy MFRC522 Simplified reading/writing data chunks from/to RFID tags with MFRC522 module.
EMUcanT4 ECUMaster EMU CAN Stream Reader Arduino Teensy 4 Library
FirebaseJson The easiest Arduino library JSON parser, builder and editor for ESP8266, ESP32, Teensy 3.x, Teensy 4.x and others MCUs.
GUIslice GUIslice embedded touchscreen GUI library in C for Arduino & Raspberry Pi
Hello Drum Arduino Library for piezo sensing
Lepton FLiR Thermal Camera Module Library Library to control a Lepton FLiR (forward looking infrared) thermal camera module from an Arduino-like board (Teensy 3+/ESP32+ minimum).
Mcp3208 Arduino library for the MCP320x 12 bit ADC family.
MFRC522 Arduino RFID Library for MFRC522 (SPI)
MFRC522-spi-i2c-uart-async Arduino RFID Library for MFRC522 (SPI, I2C and UART) with asynchroneous callbacks
PJON PJON is an open-source, multi-master, multi-media bus network protocol
RFID_MFRC522v2 Arduino RFID driver library for MFRC522 (SPI, I2C)
TeensyID A library for getting Teensy IDs
Teensy_Slow_PWM This library enables you to use ISR-based PWM channels on Teensy boards, such as Teensy 2.x, Teensy LC, Teensy 3.x, Teensy 4.x, Teensy MicroMod, etc., to create and output PWM any GPIO pin.
Teensy_TimerInterrupt This library enables you to use Interrupt from Hardware Timers on a Teensy-based board such as Teensy 4.x, 3.x, LC, 2.0, etc.
TimerInterrupt This library enables you to use Interrupt from Hardware Timers on an Arduino, Adafruit or Sparkfun AVR board, such as Nano, UNO, Mega, Leonardo, YUN, Teensy, Feather_32u4, Feather_328P, Pro Micro, etc.
U8glib-HAL A library supporting monochrome TFTs and OLEDs, specifically for use with Marlin Firmware.
Watchdog Watchdog resets the device if the timer expires before the watchdog is reset.