Build on Ubuntu On Windows10
You can build tmk_keyboard firmware with Bash on Windows.
NOTE: dfu-programmer doesn't work in Ubuntu on Windows 10 :( at this time at least. You can not flash your microcontroller inside ubuntu unfotunately. You need Windows native tool like Atmel FLIP or dfu-programmer to program microcontroller.
http://www.howtogeek.com/249966/how-to-install-and-use-the-linux-bash-shell-on-windows-10/
Open Bash window form start menu and install build tools.
$ sudo apt-get update
$ sudo apt-get upgrade
$ sudo apt-get install -y git unzip build-essential
$ sudo apt-get install -y make gcc-avr avr-libc binutils-avr dfu-programmer
$ sudo apt-get install -y binutils-arm-none-eabi gcc-arm-none-eabi libnewlib-arm-none-eabi libstdc++-arm-none-eabi-newlib dfu-util
$ sudo apt-get autoremove
$ sudo apt-get clean
Get source codes from github and place under your home folder.
$ cd /mnt/c/Users/<yourname>
$ git clone https://github.com/tmk/tmk_keyboard.git
And build firmware, for example.
$ cd tmk_keyboard/keyboard/hhkb
$ make
You can access the firmware under home folder through Explorer.
You can access all files on ubuntu under this holder.
C:\Users\<yourname>\AppData\Local\lxss\
But the holder is invisible from Explorer, you can have to type the path directly in address bar.