Here is a first beta test for Teensyduino 1.41.

Old beta download links removed. Please use the latest version:

Changes since Teensyduino 1.40:

Add IntervalTimer update()
Ethernet fix socket receive state caching bug
Ethernet improve handling of unexpected remote server disconnect
SD fix timeouts
SPI pin changes kept in sync with AVR SPI emulation
SPI avoid interfere with pin 45
Wire force recovery from stuck slave devices
Wire improve detection of arbitration loss to other bus masters
Add AudioConnection disconnect() (thanks b0rg3rt)
Update platform.txt for compatibility with Arduino 1.9 beta
Fix serial stall if higher than maximum baud rate configured
Improve delayMicroseconds on Teensy 2.0 (Graham)
Fix SERIAL_8N2 mode on Teensy LC
Update sample Makefile
Add abort() function, needed for Pozyx library
Update keywords for Serial formats & USB Keyboard special keys
Improve AVR SPI register emulation, speed bits
Fix tone() issue when 0 Hz requested, minimum is 1 Hz
Fix Teensy LC DMAChannel bug (thanks kbob)
Audio add ADAT output (thanks Ernstjan Freriks)
Audio fix RMS analysis when no data
Audio ToneSweep improvements (thanks Pio)
Audio design tool custom name bug fixed (thanks neurofun)
Audio modulated sine amplitude when no mod signal fix (thanks neurofun)
Audio library documentation updated, several minor errors fixed
FastLED updated to support WS2812Serial
Time library minor updates & fixes
i2c_t3 library updated
OctoWS2811 fix on Teensy 3.5
OctoWS2811 remove unnecessary delay
OctoWS2811 improve setPixel speed (thanks sgorsh)
USBHost_t36 support for CDC-ACM, PL2303 & CH341 serial (thanks KurtE)
USBHost_t36 support for RawHID (thanks KurtE)
USBHost_t36 support for Xbox One controller (thanks KurtE)
USBHost_t36 improve keyboard & joystick support (thanks KurtE)
USBHost_t36 fix USB MIDI fast data input
USBHost_t36 Ant+ wireless adaptor support (adapted from Michael McElligott)
USBHost_t36 access to device ID and name (thanks KurtE)
XPT2046_Touchscreen detect touch by interrupts (thanks Donziboy2 & Defragster)