kudos to Jantje for Eclipse Arduino IDE and thanks to headroom for instructions pages. I've finally gotten all of the steps done and I appear to be able to build the blink example. I'm developing on Ubuntu 12.04.

However, when i try to upload Teensy bootloader complains

Error: "blink.hex" is not compled for this board.
Compiled for: "Teensy 3.0 (MK20DX128)"
This board is: "Teensy 3.1 (MK20DX256)"

I noticed in .../teensy/all/boards.txt there is no specific mention of teensy 3.1, so I tried making the following changes:
o changed "teensy3.name=Teensy 3.0" to "teensy3.name=Teensy 3.1"
o all occurrences of 128 to 256, where it appeard in MK20DX<> string.

But this did not seem to have any affect.

Any suggestions? Thanks in advance.

How in general, do I convert this setup from teensy 3.0 to teensy 3.1, even though they are supposedly code compatible?